From nobody Mon Jun 15 00:03:25 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94E42C433FE for ; Mon, 9 May 2022 18:38:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240255AbiEISmb (ORCPT ); Mon, 9 May 2022 14:42:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240192AbiEISm1 (ORCPT ); Mon, 9 May 2022 14:42:27 -0400 Received: from out0.migadu.com (out0.migadu.com [IPv6:2001:41d0:2:267::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D3F4D26084D for ; Mon, 9 May 2022 11:38:32 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1652121511; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=E7yqlEFZDQsrcQFeTz8EFzx9rgYk0i5CEIpAH0i4ulA=; b=xl/szZ3Ak9hLsVXMZIyVLhsP7L6EdVYibFE1x6wt/+BDQrOlFwGeFlXbNuS8zeDDqZaNO9 JTCF9fGQGAUFA6fms/EFouu/UD2j1FYFlaP7xNjt773pfH2P2sonCkG9i3+Kd0NxDcjz71 tWqMIBNy1sQ1DVBhaeW2qXhI9AZACRs= From: Roman Gushchin To: Andrew Morton , linux-mm@kvack.org Cc: Dave Chinner , linux-kernel@vger.kernel.org, Kent Overstreet , Hillf Danton , Christophe JAILLET , Roman Gushchin Subject: [PATCH v3 1/6] mm: memcontrol: introduce mem_cgroup_ino() and mem_cgroup_get_from_ino() Date: Mon, 9 May 2022 11:38:15 -0700 Message-Id: <20220509183820.573666-2-roman.gushchin@linux.dev> In-Reply-To: <20220509183820.573666-1-roman.gushchin@linux.dev> References: <20220509183820.573666-1-roman.gushchin@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Shrinker debugfs requires a way to represent memory cgroups without using full paths, both for displaying information and getting input from a user. Cgroup inode number is a perfect way, already used by bpf. This commit adds a couple of helper functions which will be used to handle memcg-aware shrinkers. Signed-off-by: Roman Gushchin --- include/linux/memcontrol.h | 21 +++++++++++++++++++++ mm/memcontrol.c | 23 +++++++++++++++++++++++ 2 files changed, 44 insertions(+) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index fe580cb96683..a6de9e5c1549 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -831,6 +831,15 @@ static inline unsigned short mem_cgroup_id(struct mem_= cgroup *memcg) } struct mem_cgroup *mem_cgroup_from_id(unsigned short id); =20 +#ifdef CONFIG_SHRINKER_DEBUG +static inline unsigned long mem_cgroup_ino(struct mem_cgroup *memcg) +{ + return memcg ? cgroup_ino(memcg->css.cgroup) : 0; +} + +struct mem_cgroup *mem_cgroup_get_from_ino(unsigned long ino); +#endif + static inline struct mem_cgroup *mem_cgroup_from_seq(struct seq_file *m) { return mem_cgroup_from_css(seq_css(m)); @@ -1324,6 +1333,18 @@ static inline struct mem_cgroup *mem_cgroup_from_id(= unsigned short id) return NULL; } =20 +#ifdef CONFIG_SHRINKER_DEBUG +static inline unsigned long mem_cgroup_ino(struct mem_cgroup *memcg) +{ + return 0; +} + +static inline struct mem_cgroup *mem_cgroup_get_from_ino(unsigned long ino) +{ + return NULL; +} +#endif + static inline struct mem_cgroup *mem_cgroup_from_seq(struct seq_file *m) { return NULL; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 04cea4fa362a..e6472728fa66 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5018,6 +5018,29 @@ struct mem_cgroup *mem_cgroup_from_id(unsigned short= id) return idr_find(&mem_cgroup_idr, id); } =20 +#ifdef CONFIG_SHRINKER_DEBUG +struct mem_cgroup *mem_cgroup_get_from_ino(unsigned long ino) +{ + struct cgroup *cgrp; + struct cgroup_subsys_state *css; + struct mem_cgroup *memcg; + + cgrp =3D cgroup_get_from_id(ino); + if (!cgrp) + return ERR_PTR(-ENOENT); + + css =3D cgroup_get_e_css(cgrp, &memory_cgrp_subsys); + if (css) + memcg =3D container_of(css, struct mem_cgroup, css); + else + memcg =3D ERR_PTR(-ENOENT); + + cgroup_put(cgrp); + + return memcg; +} +#endif + static int alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int no= de) { struct mem_cgroup_per_node *pn; --=20 2.35.3 From nobody Mon Jun 15 00:03:25 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 671BAC433EF for ; Mon, 9 May 2022 18:38:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240265AbiEISmg (ORCPT ); Mon, 9 May 2022 14:42:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240253AbiEISmb (ORCPT ); Mon, 9 May 2022 14:42:31 -0400 Received: from out0.migadu.com (out0.migadu.com [94.23.1.103]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C76B4260846 for ; Mon, 9 May 2022 11:38:35 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1652121514; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=sxLMfKpQ848b7WLURetwS8PllL8MpoU17iYNNHb2Sj0=; b=RmZG20Dq86giIWBm1RVLnIqjPHfk1tiyMxFypQGkMJAiDYqOvRBaweHbFYIt0UbSWzxDyj VhldFjgmG2f1MToh3CVVgjScak1DzosgTJO0w/DYPVTXiq4+Np493FLcgALoPRuvF1e2MX o9rfLtz1OP0i3LUI0Emilffu0PqCGyo= From: Roman Gushchin To: Andrew Morton , linux-mm@kvack.org Cc: Dave Chinner , linux-kernel@vger.kernel.org, Kent Overstreet , Hillf Danton , Christophe JAILLET , Roman Gushchin Subject: [PATCH v3 2/6] mm: shrinkers: introduce debugfs interface for memory shrinkers Date: Mon, 9 May 2022 11:38:16 -0700 Message-Id: <20220509183820.573666-3-roman.gushchin@linux.dev> In-Reply-To: <20220509183820.573666-1-roman.gushchin@linux.dev> References: <20220509183820.573666-1-roman.gushchin@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: ... ... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. Signed-off-by: Roman Gushchin Reviewed-by: Kent Overstreet --- include/linux/shrinker.h | 19 ++++- lib/Kconfig.debug | 9 +++ mm/Makefile | 1 + mm/shrinker_debug.c | 171 +++++++++++++++++++++++++++++++++++++++ mm/vmscan.c | 6 +- 5 files changed, 203 insertions(+), 3 deletions(-) create mode 100644 mm/shrinker_debug.c diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h index 76fbf92b04d9..2ced8149c513 100644 --- a/include/linux/shrinker.h +++ b/include/linux/shrinker.h @@ -72,6 +72,10 @@ struct shrinker { #ifdef CONFIG_MEMCG /* ID in shrinker_idr */ int id; +#endif +#ifdef CONFIG_SHRINKER_DEBUG + int debugfs_id; + struct dentry *debugfs_entry; #endif /* objs pending delete, per node */ atomic_long_t *nr_deferred; @@ -94,4 +98,17 @@ extern int register_shrinker(struct shrinker *shrinker); extern void unregister_shrinker(struct shrinker *shrinker); extern void free_prealloced_shrinker(struct shrinker *shrinker); extern void synchronize_shrinkers(void); -#endif + +#ifdef CONFIG_SHRINKER_DEBUG +extern int shrinker_debugfs_add(struct shrinker *shrinker); +extern void shrinker_debugfs_remove(struct shrinker *shrinker); +#else /* CONFIG_SHRINKER_DEBUG */ +static inline int shrinker_debugfs_add(struct shrinker *shrinker) +{ + return 0; +} +static inline void shrinker_debugfs_remove(struct shrinker *shrinker) +{ +} +#endif /* CONFIG_SHRINKER_DEBUG */ +#endif /* _LINUX_SHRINKER_H */ diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 3fd7a2e9eaf1..5fa65a649798 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -733,6 +733,15 @@ config SLUB_STATS out which slabs are relevant to a particular load. Try running: slabinfo -DA =20 +config SHRINKER_DEBUG + default y + bool "Enable shrinker debugging support" + depends on DEBUG_FS + help + Say Y to enable the shrinker debugfs interface which provides + visibility into the kernel memory shrinkers subsystem. + Disable it to avoid an extra memory footprint. + config HAVE_DEBUG_KMEMLEAK bool =20 diff --git a/mm/Makefile b/mm/Makefile index 298c9991ab75..8083fa85a348 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -133,3 +133,4 @@ obj-$(CONFIG_PAGE_REPORTING) +=3D page_reporting.o obj-$(CONFIG_IO_MAPPING) +=3D io-mapping.o obj-$(CONFIG_HAVE_BOOTMEM_INFO_NODE) +=3D bootmem_info.o obj-$(CONFIG_GENERIC_IOREMAP) +=3D ioremap.o +obj-$(CONFIG_SHRINKER_DEBUG) +=3D shrinker_debug.o diff --git a/mm/shrinker_debug.c b/mm/shrinker_debug.c new file mode 100644 index 000000000000..fd1f805a581a --- /dev/null +++ b/mm/shrinker_debug.c @@ -0,0 +1,171 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include + +/* defined in vmscan.c */ +extern struct rw_semaphore shrinker_rwsem; +extern struct list_head shrinker_list; + +static DEFINE_IDA(shrinker_debugfs_ida); +static struct dentry *shrinker_debugfs_root; + +static unsigned long shrinker_count_objects(struct shrinker *shrinker, + struct mem_cgroup *memcg, + unsigned long *count_per_node) +{ + unsigned long nr, total =3D 0; + int nid; + + for_each_node(nid) { + if (nid =3D=3D 0 || (shrinker->flags & SHRINKER_NUMA_AWARE)) { + struct shrink_control sc =3D { + .gfp_mask =3D GFP_KERNEL, + .nid =3D nid, + .memcg =3D memcg, + }; + + nr =3D shrinker->count_objects(shrinker, &sc); + if (nr =3D=3D SHRINK_EMPTY) + nr =3D 0; + } else { + nr =3D 0; + } + + count_per_node[nid] =3D nr; + total +=3D nr; + } + + return total; +} + +static int shrinker_debugfs_count_show(struct seq_file *m, void *v) +{ + struct shrinker *shrinker =3D (struct shrinker *)m->private; + unsigned long *count_per_node =3D NULL; + struct mem_cgroup *memcg; + unsigned long total; + bool memcg_aware; + int ret, nid; + + count_per_node =3D kcalloc(nr_node_ids, sizeof(unsigned long), GFP_KERNEL= ); + if (!count_per_node) + return -ENOMEM; + + ret =3D down_read_killable(&shrinker_rwsem); + if (ret) { + kfree(count_per_node); + return ret; + } + rcu_read_lock(); + + memcg_aware =3D shrinker->flags & SHRINKER_MEMCG_AWARE; + + memcg =3D mem_cgroup_iter(NULL, NULL, NULL); + do { + if (memcg && !mem_cgroup_online(memcg)) + continue; + + total =3D shrinker_count_objects(shrinker, + memcg_aware ? memcg : NULL, + count_per_node); + if (total) { + seq_printf(m, "%lu", mem_cgroup_ino(memcg)); + for_each_node(nid) + seq_printf(m, " %lu", count_per_node[nid]); + seq_puts(m, "\n"); + } + + if (!memcg_aware) { + mem_cgroup_iter_break(NULL, memcg); + break; + } + + if (signal_pending(current)) { + mem_cgroup_iter_break(NULL, memcg); + ret =3D -EINTR; + break; + } + + cond_resched(); + } while ((memcg =3D mem_cgroup_iter(NULL, memcg, NULL)) !=3D NULL); + + rcu_read_unlock(); + up_read(&shrinker_rwsem); + + kfree(count_per_node); + return ret; +} +DEFINE_SHOW_ATTRIBUTE(shrinker_debugfs_count); + +int shrinker_debugfs_add(struct shrinker *shrinker) +{ + struct dentry *entry; + char buf[16]; + int id; + + lockdep_assert_held(&shrinker_rwsem); + + /* debugfs isn't initialized yet, add debugfs entries later. */ + if (!shrinker_debugfs_root) + return 0; + + id =3D ida_alloc(&shrinker_debugfs_ida, GFP_KERNEL); + if (id < 0) + return id; + shrinker->debugfs_id =3D id; + + snprintf(buf, sizeof(buf), "%d", id); + + /* create debugfs entry */ + entry =3D debugfs_create_dir(buf, shrinker_debugfs_root); + if (IS_ERR(entry)) { + ida_free(&shrinker_debugfs_ida, id); + return PTR_ERR(entry); + } + shrinker->debugfs_entry =3D entry; + + debugfs_create_file("count", 0220, entry, shrinker, + &shrinker_debugfs_count_fops); + return 0; +} + +void shrinker_debugfs_remove(struct shrinker *shrinker) +{ + lockdep_assert_held(&shrinker_rwsem); + + if (!shrinker->debugfs_entry) + return; + + debugfs_remove_recursive(shrinker->debugfs_entry); + ida_free(&shrinker_debugfs_ida, shrinker->debugfs_id); +} + +static int __init shrinker_debugfs_init(void) +{ + struct shrinker *shrinker; + int ret; + + if (!debugfs_initialized()) + return -ENODEV; + + shrinker_debugfs_root =3D debugfs_create_dir("shrinker", NULL); + if (!shrinker_debugfs_root) + return -ENOMEM; + + /* Create debugfs entries for shrinkers registered at boot */ + ret =3D down_write_killable(&shrinker_rwsem); + if (ret) + return ret; + + list_for_each_entry(shrinker, &shrinker_list, list) + if (!shrinker->debugfs_entry) + ret =3D shrinker_debugfs_add(shrinker); + up_write(&shrinker_rwsem); + + return ret; +} +late_initcall(shrinker_debugfs_init); diff --git a/mm/vmscan.c b/mm/vmscan.c index c6918fff06e1..024f7056b98c 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -190,8 +190,8 @@ static void set_task_reclaim_state(struct task_struct *= task, task->reclaim_state =3D rs; } =20 -static LIST_HEAD(shrinker_list); -static DECLARE_RWSEM(shrinker_rwsem); +LIST_HEAD(shrinker_list); +DECLARE_RWSEM(shrinker_rwsem); =20 #ifdef CONFIG_MEMCG static int shrinker_nr_max; @@ -655,6 +655,7 @@ void register_shrinker_prepared(struct shrinker *shrink= er) down_write(&shrinker_rwsem); list_add_tail(&shrinker->list, &shrinker_list); shrinker->flags |=3D SHRINKER_REGISTERED; + WARN_ON_ONCE(shrinker_debugfs_add(shrinker)); up_write(&shrinker_rwsem); } =20 @@ -682,6 +683,7 @@ void unregister_shrinker(struct shrinker *shrinker) shrinker->flags &=3D ~SHRINKER_REGISTERED; if (shrinker->flags & SHRINKER_MEMCG_AWARE) unregister_memcg_shrinker(shrinker); + shrinker_debugfs_remove(shrinker); up_write(&shrinker_rwsem); =20 kfree(shrinker->nr_deferred); --=20 2.35.3 From nobody Mon Jun 15 00:03:25 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2DEF0C433EF for ; Mon, 9 May 2022 18:38:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240271AbiEISmi (ORCPT ); Mon, 9 May 2022 14:42:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42028 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240262AbiEISmg (ORCPT ); Mon, 9 May 2022 14:42:36 -0400 Received: from out0.migadu.com (out0.migadu.com [94.23.1.103]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 41420260853 for ; Mon, 9 May 2022 11:38:39 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1652121517; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Tyhh2OHymvIq37sH5N3NRdUNT5qZMHI1F4No9qhX9Sw=; b=D/qcc2tehbeLuFQazfl/xsW+0ghCwrkhWP5JAjOp0ATXodQdSoHFnVmjgK0NwrVYYlFfFy Tyyu8D8eV+Y6GMSJLaUupmtz/tQ+IFjKgkWY0gE5ieNstUnNC901IvFBe8QpVXWMG2KJg+ GSrmg7gR1DlBODab3Tzo+oTKE6fTmbM= From: Roman Gushchin To: Andrew Morton , linux-mm@kvack.org Cc: Dave Chinner , linux-kernel@vger.kernel.org, Kent Overstreet , Hillf Danton , Christophe JAILLET , Roman Gushchin Subject: [PATCH v3 3/6] mm: shrinkers: provide shrinkers with names Date: Mon, 9 May 2022 11:38:17 -0700 Message-Id: <20220509183820.573666-4-roman.gushchin@linux.dev> In-Reply-To: <20220509183820.573666-1-roman.gushchin@linux.dev> References: <20220509183820.573666-1-roman.gushchin@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Currently shrinkers are anonymous objects. For debugging purposes they can be identified by count/scan function names, but it's not always useful: e.g. for superblock's shrinkers it's nice to have at least an idea of to which superblock the shrinker belongs. This commit adds names to shrinkers. register_shrinker() and prealloc_shrinker() functions are extended to take a format and arguments to master a name. In some cases it's not possible to determine a good name at the time when a shrinker is allocated. For such cases shrinker_debugfs_rename() is provided. After this change the shrinker debugfs directory looks like: $ cd /sys/kernel/debug/shrinker/ $ ls dqcache-16 sb-hugetlbfs-17 sb-rootfs-2 sb-tmpfs-50 kfree_rcu-0 sb-hugetlbfs-33 sb-securityfs-6 sb-tracefs-13 sb-aio-20 sb-iomem-12 sb-selinuxfs-22 sb-xfs:vda1-36 sb-anon_inodefs-15 sb-mqueue-21 sb-sockfs-8 sb-zsmalloc-19 sb-bdev-3 sb-nsfs-4 sb-sysfs-26 shadow-18 sb-bpf-32 sb-pipefs-14 sb-tmpfs-1 thp_deferred_spli= t-10 sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-27 thp_zero-9 sb-cgroup2-30 sb-proc-39 sb-tmpfs-29 xfs_buf-37 sb-configfs-23 sb-proc-41 sb-tmpfs-35 xfs_inodegc-38 sb-dax-11 sb-proc-45 sb-tmpfs-40 zspool-34 sb-debugfs-7 sb-proc-46 sb-tmpfs-42 sb-devpts-28 sb-proc-47 sb-tmpfs-43 sb-devtmpfs-5 sb-pstore-31 sb-tmpfs-44 Signed-off-by: Roman Gushchin --- arch/x86/kvm/mmu/mmu.c | 2 +- drivers/android/binder_alloc.c | 2 +- drivers/gpu/drm/i915/gem/i915_gem_shrinker.c | 3 +- drivers/gpu/drm/msm/msm_gem_shrinker.c | 2 +- .../gpu/drm/panfrost/panfrost_gem_shrinker.c | 2 +- drivers/gpu/drm/ttm/ttm_pool.c | 2 +- drivers/md/bcache/btree.c | 2 +- drivers/md/dm-bufio.c | 2 +- drivers/md/dm-zoned-metadata.c | 2 +- drivers/md/raid5.c | 2 +- drivers/misc/vmw_balloon.c | 2 +- drivers/virtio/virtio_balloon.c | 2 +- drivers/xen/xenbus/xenbus_probe_backend.c | 2 +- fs/btrfs/super.c | 2 + fs/erofs/utils.c | 2 +- fs/ext4/extents_status.c | 3 +- fs/f2fs/super.c | 2 +- fs/gfs2/glock.c | 2 +- fs/gfs2/main.c | 2 +- fs/jbd2/journal.c | 2 +- fs/mbcache.c | 2 +- fs/nfs/nfs42xattr.c | 7 ++- fs/nfs/super.c | 2 +- fs/nfsd/filecache.c | 2 +- fs/nfsd/nfscache.c | 2 +- fs/quota/dquot.c | 2 +- fs/super.c | 6 +- fs/ubifs/super.c | 2 +- fs/xfs/xfs_buf.c | 2 +- fs/xfs/xfs_icache.c | 2 +- fs/xfs/xfs_qm.c | 2 +- include/linux/shrinker.h | 12 +++- kernel/rcu/tree.c | 2 +- mm/huge_memory.c | 4 +- mm/shrinker_debug.c | 45 +++++++++++++- mm/vmscan.c | 58 ++++++++++++++++++- mm/workingset.c | 2 +- mm/zsmalloc.c | 2 +- net/sunrpc/auth.c | 2 +- 39 files changed, 154 insertions(+), 46 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index c623019929a7..8cfabdd63406 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -6283,7 +6283,7 @@ int kvm_mmu_vendor_module_init(void) if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL)) goto out; =20 - ret =3D register_shrinker(&mmu_shrinker); + ret =3D register_shrinker(&mmu_shrinker, "mmu"); if (ret) goto out; =20 diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c index 2ac1008a5f39..951343c41ba8 100644 --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -1084,7 +1084,7 @@ int binder_alloc_shrinker_init(void) int ret =3D list_lru_init(&binder_alloc_lru); =20 if (ret =3D=3D 0) { - ret =3D register_shrinker(&binder_shrinker); + ret =3D register_shrinker(&binder_shrinker, "binder"); if (ret) list_lru_destroy(&binder_alloc_lru); } diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c b/drivers/gpu/drm= /i915/gem/i915_gem_shrinker.c index 6a6ff98a8746..85524ef92ea4 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c @@ -426,7 +426,8 @@ void i915_gem_driver_register__shrinker(struct drm_i915= _private *i915) i915->mm.shrinker.count_objects =3D i915_gem_shrinker_count; i915->mm.shrinker.seeks =3D DEFAULT_SEEKS; i915->mm.shrinker.batch =3D 4096; - drm_WARN_ON(&i915->drm, register_shrinker(&i915->mm.shrinker)); + drm_WARN_ON(&i915->drm, register_shrinker(&i915->mm.shrinker, + "drm_i915_gem")); =20 i915->mm.oom_notifier.notifier_call =3D i915_gem_shrinker_oom; drm_WARN_ON(&i915->drm, register_oom_notifier(&i915->mm.oom_notifier)); diff --git a/drivers/gpu/drm/msm/msm_gem_shrinker.c b/drivers/gpu/drm/msm/m= sm_gem_shrinker.c index 086dacf2f26a..2d3cf4f13dfd 100644 --- a/drivers/gpu/drm/msm/msm_gem_shrinker.c +++ b/drivers/gpu/drm/msm/msm_gem_shrinker.c @@ -221,7 +221,7 @@ void msm_gem_shrinker_init(struct drm_device *dev) priv->shrinker.count_objects =3D msm_gem_shrinker_count; priv->shrinker.scan_objects =3D msm_gem_shrinker_scan; priv->shrinker.seeks =3D DEFAULT_SEEKS; - WARN_ON(register_shrinker(&priv->shrinker)); + WARN_ON(register_shrinker(&priv->shrinker, "drm_msm_gem")); =20 priv->vmap_notifier.notifier_call =3D msm_gem_shrinker_vmap; WARN_ON(register_vmap_purge_notifier(&priv->vmap_notifier)); diff --git a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c b/drivers/gpu= /drm/panfrost/panfrost_gem_shrinker.c index 77e7cb6d1ae3..0d028266ee9e 100644 --- a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c +++ b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c @@ -103,7 +103,7 @@ void panfrost_gem_shrinker_init(struct drm_device *dev) pfdev->shrinker.count_objects =3D panfrost_gem_shrinker_count; pfdev->shrinker.scan_objects =3D panfrost_gem_shrinker_scan; pfdev->shrinker.seeks =3D DEFAULT_SEEKS; - WARN_ON(register_shrinker(&pfdev->shrinker)); + WARN_ON(register_shrinker(&pfdev->shrinker, "drm_panfrost")); } =20 /** diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c index 1bba0a0ed3f9..b8b41d242197 100644 --- a/drivers/gpu/drm/ttm/ttm_pool.c +++ b/drivers/gpu/drm/ttm/ttm_pool.c @@ -722,7 +722,7 @@ int ttm_pool_mgr_init(unsigned long num_pages) mm_shrinker.count_objects =3D ttm_pool_shrinker_count; mm_shrinker.scan_objects =3D ttm_pool_shrinker_scan; mm_shrinker.seeks =3D 1; - return register_shrinker(&mm_shrinker); + return register_shrinker(&mm_shrinker, "drm_ttm_pool"); } =20 /** diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c index ad9f16689419..c1f734ab86b3 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -812,7 +812,7 @@ int bch_btree_cache_alloc(struct cache_set *c) c->shrink.seeks =3D 4; c->shrink.batch =3D c->btree_pages * 2; =20 - if (register_shrinker(&c->shrink)) + if (register_shrinker(&c->shrink, "btree")) pr_warn("bcache: %s: could not register shrinker\n", __func__); =20 diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index 5ffa1dcf84cf..bcc95898c341 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -1806,7 +1806,7 @@ struct dm_bufio_client *dm_bufio_client_create(struct= block_device *bdev, unsign c->shrinker.scan_objects =3D dm_bufio_shrink_scan; c->shrinker.seeks =3D 1; c->shrinker.batch =3D 0; - r =3D register_shrinker(&c->shrinker); + r =3D register_shrinker(&c->shrinker, "dm_bufio"); if (r) goto bad; =20 diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c index d1ea66114d14..05f2fd12066b 100644 --- a/drivers/md/dm-zoned-metadata.c +++ b/drivers/md/dm-zoned-metadata.c @@ -2944,7 +2944,7 @@ int dmz_ctr_metadata(struct dmz_dev *dev, int num_dev, zmd->mblk_shrinker.seeks =3D DEFAULT_SEEKS; =20 /* Metadata cache shrinker */ - ret =3D register_shrinker(&zmd->mblk_shrinker); + ret =3D register_shrinker(&zmd->mblk_shrinker, "md_meta"); if (ret) { dmz_zmd_err(zmd, "Register metadata cache shrinker failed"); goto err; diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 59f91e392a2a..34ddebd3aff7 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -7383,7 +7383,7 @@ static struct r5conf *setup_conf(struct mddev *mddev) conf->shrinker.count_objects =3D raid5_cache_count; conf->shrinker.batch =3D 128; conf->shrinker.flags =3D 0; - if (register_shrinker(&conf->shrinker)) { + if (register_shrinker(&conf->shrinker, "md-%s", mdname(mddev))) { pr_warn("md/raid:%s: couldn't register shrinker.\n", mdname(mddev)); goto abort; diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c index f1d8ba6d4857..6c9ddf1187dd 100644 --- a/drivers/misc/vmw_balloon.c +++ b/drivers/misc/vmw_balloon.c @@ -1587,7 +1587,7 @@ static int vmballoon_register_shrinker(struct vmballo= on *b) b->shrinker.count_objects =3D vmballoon_shrinker_count; b->shrinker.seeks =3D DEFAULT_SEEKS; =20 - r =3D register_shrinker(&b->shrinker); + r =3D register_shrinker(&b->shrinker, "vmw_balloon"); =20 if (r =3D=3D 0) b->shrinker_registered =3D true; diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloo= n.c index f4c34a2a6b8e..093e06e19d0e 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -875,7 +875,7 @@ static int virtio_balloon_register_shrinker(struct virt= io_balloon *vb) vb->shrinker.count_objects =3D virtio_balloon_shrinker_count; vb->shrinker.seeks =3D DEFAULT_SEEKS; =20 - return register_shrinker(&vb->shrinker); + return register_shrinker(&vb->shrinker, "virtio_valloon"); } =20 static int virtballoon_probe(struct virtio_device *vdev) diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus= /xenbus_probe_backend.c index 5abded97e1a7..a6c5e344017d 100644 --- a/drivers/xen/xenbus/xenbus_probe_backend.c +++ b/drivers/xen/xenbus/xenbus_probe_backend.c @@ -305,7 +305,7 @@ static int __init xenbus_probe_backend_init(void) =20 register_xenstore_notifier(&xenstore_notifier); =20 - if (register_shrinker(&backend_memory_shrinker)) + if (register_shrinker(&backend_memory_shrinker, "xen_backend")) pr_warn("shrinker registration failed\n"); =20 return 0; diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 206f44005c52..062dbd8071e2 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1790,6 +1790,8 @@ static struct dentry *btrfs_mount_root(struct file_sy= stem_type *fs_type, error =3D -EBUSY; } else { snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev); + shrinker_debugfs_rename(&s->s_shrink, "sb-%s:%s", fs_type->name, + s->s_id); btrfs_sb(s)->bdev_holder =3D fs_type; if (!strstr(crc32c_impl(), "generic")) set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags); diff --git a/fs/erofs/utils.c b/fs/erofs/utils.c index ec9a1d780dc1..67eb64fadd4f 100644 --- a/fs/erofs/utils.c +++ b/fs/erofs/utils.c @@ -282,7 +282,7 @@ static struct shrinker erofs_shrinker_info =3D { =20 int __init erofs_init_shrinker(void) { - return register_shrinker(&erofs_shrinker_info); + return register_shrinker(&erofs_shrinker_info, "erofs"); } =20 void erofs_exit_shrinker(void) diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c index 9a3a8996aacf..a7aa79d580e5 100644 --- a/fs/ext4/extents_status.c +++ b/fs/ext4/extents_status.c @@ -1650,11 +1650,10 @@ int ext4_es_register_shrinker(struct ext4_sb_info *= sbi) err =3D percpu_counter_init(&sbi->s_es_stats.es_stats_shk_cnt, 0, GFP_KER= NEL); if (err) goto err3; - sbi->s_es_shrinker.scan_objects =3D ext4_es_scan; sbi->s_es_shrinker.count_objects =3D ext4_es_count; sbi->s_es_shrinker.seeks =3D DEFAULT_SEEKS; - err =3D register_shrinker(&sbi->s_es_shrinker); + err =3D register_shrinker(&sbi->s_es_shrinker, "ext4_es"); if (err) goto err4; =20 diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 4368f90571bd..2fc40a1635f3 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -4579,7 +4579,7 @@ static int __init init_f2fs_fs(void) err =3D f2fs_init_sysfs(); if (err) goto free_garbage_collection_cache; - err =3D register_shrinker(&f2fs_shrinker_info); + err =3D register_shrinker(&f2fs_shrinker_info, "f2fs"); if (err) goto free_sysfs; err =3D register_filesystem(&f2fs_fs_type); diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 26169cedcefc..791c23d9f7e7 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -2549,7 +2549,7 @@ int __init gfs2_glock_init(void) return -ENOMEM; } =20 - ret =3D register_shrinker(&glock_shrinker); + ret =3D register_shrinker(&glock_shrinker, "gfs2_glock"); if (ret) { destroy_workqueue(gfs2_delete_workqueue); destroy_workqueue(glock_workqueue); diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c index 28d0eb23e18e..dde981b78488 100644 --- a/fs/gfs2/main.c +++ b/fs/gfs2/main.c @@ -150,7 +150,7 @@ static int __init init_gfs2_fs(void) if (!gfs2_trans_cachep) goto fail_cachep8; =20 - error =3D register_shrinker(&gfs2_qd_shrinker); + error =3D register_shrinker(&gfs2_qd_shrinker, "gfs2_qd"); if (error) goto fail_shrinker; =20 diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index c0cbeeaec2d1..e7786445ecc1 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1418,7 +1418,7 @@ static journal_t *journal_init_common(struct block_de= vice *bdev, if (percpu_counter_init(&journal->j_checkpoint_jh_count, 0, GFP_KERNEL)) goto err_cleanup; =20 - if (register_shrinker(&journal->j_shrinker)) { + if (register_shrinker(&journal->j_shrinker, "jbd2_journal")) { percpu_counter_destroy(&journal->j_checkpoint_jh_count); goto err_cleanup; } diff --git a/fs/mbcache.c b/fs/mbcache.c index 97c54d3a2227..379dc5b0b6ad 100644 --- a/fs/mbcache.c +++ b/fs/mbcache.c @@ -367,7 +367,7 @@ struct mb_cache *mb_cache_create(int bucket_bits) cache->c_shrink.count_objects =3D mb_cache_count; cache->c_shrink.scan_objects =3D mb_cache_scan; cache->c_shrink.seeks =3D DEFAULT_SEEKS; - if (register_shrinker(&cache->c_shrink)) { + if (register_shrinker(&cache->c_shrink, "mb_cache")) { kfree(cache->c_hash); kfree(cache); goto err_out; diff --git a/fs/nfs/nfs42xattr.c b/fs/nfs/nfs42xattr.c index e7b34f7e0614..147b8a2f2dc6 100644 --- a/fs/nfs/nfs42xattr.c +++ b/fs/nfs/nfs42xattr.c @@ -1017,15 +1017,16 @@ int __init nfs4_xattr_cache_init(void) if (ret) goto out2; =20 - ret =3D register_shrinker(&nfs4_xattr_cache_shrinker); + ret =3D register_shrinker(&nfs4_xattr_cache_shrinker, "nfs_xattr_cache"); if (ret) goto out1; =20 - ret =3D register_shrinker(&nfs4_xattr_entry_shrinker); + ret =3D register_shrinker(&nfs4_xattr_entry_shrinker, "nfs_xattr_entry"); if (ret) goto out; =20 - ret =3D register_shrinker(&nfs4_xattr_large_entry_shrinker); + ret =3D register_shrinker(&nfs4_xattr_large_entry_shrinker, + "nfs_xattr_large_entry"); if (!ret) return 0; =20 diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 6ab5eeb000dc..c7a2aef911f1 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -149,7 +149,7 @@ int __init register_nfs_fs(void) ret =3D nfs_register_sysctl(); if (ret < 0) goto error_2; - ret =3D register_shrinker(&acl_shrinker); + ret =3D register_shrinker(&acl_shrinker, "nfs_acl"); if (ret < 0) goto error_3; #ifdef CONFIG_NFS_V4_2 diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index 2c1b027774d4..9c2879a3c3c0 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -666,7 +666,7 @@ nfsd_file_cache_init(void) goto out_err; } =20 - ret =3D register_shrinker(&nfsd_file_shrinker); + ret =3D register_shrinker(&nfsd_file_shrinker, "nfsd_filecache"); if (ret) { pr_err("nfsd: failed to register nfsd_file_shrinker: %d\n", ret); goto out_lru; diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c index 0b3f12aa37ff..f1cfb06d0be5 100644 --- a/fs/nfsd/nfscache.c +++ b/fs/nfsd/nfscache.c @@ -176,7 +176,7 @@ int nfsd_reply_cache_init(struct nfsd_net *nn) nn->nfsd_reply_cache_shrinker.scan_objects =3D nfsd_reply_cache_scan; nn->nfsd_reply_cache_shrinker.count_objects =3D nfsd_reply_cache_count; nn->nfsd_reply_cache_shrinker.seeks =3D 1; - status =3D register_shrinker(&nn->nfsd_reply_cache_shrinker); + status =3D register_shrinker(&nn->nfsd_reply_cache_shrinker, "nfsd_reply"= ); if (status) goto out_stats_destroy; =20 diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index a74aef99bd3d..854d2b1d0914 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -2985,7 +2985,7 @@ static int __init dquot_init(void) pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld," " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order)); =20 - if (register_shrinker(&dqcache_shrinker)) + if (register_shrinker(&dqcache_shrinker, "dqcache")) panic("Cannot register dquot shrinker"); =20 return 0; diff --git a/fs/super.c b/fs/super.c index 60f57c7bc0a6..4fca6657f442 100644 --- a/fs/super.c +++ b/fs/super.c @@ -265,7 +265,7 @@ static struct super_block *alloc_super(struct file_syst= em_type *type, int flags, s->s_shrink.count_objects =3D super_cache_count; s->s_shrink.batch =3D 1024; s->s_shrink.flags =3D SHRINKER_NUMA_AWARE | SHRINKER_MEMCG_AWARE; - if (prealloc_shrinker(&s->s_shrink)) + if (prealloc_shrinker(&s->s_shrink, "sb-%s", type->name)) goto fail; if (list_lru_init_memcg(&s->s_dentry_lru, &s->s_shrink)) goto fail; @@ -1288,6 +1288,8 @@ int get_tree_bdev(struct fs_context *fc, } else { s->s_mode =3D mode; snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev); + shrinker_debugfs_rename(&s->s_shrink, "sb-%s:%s", + fc->fs_type->name, s->s_id); sb_set_blocksize(s, block_size(bdev)); error =3D fill_super(s, fc); if (error) { @@ -1363,6 +1365,8 @@ struct dentry *mount_bdev(struct file_system_type *fs= _type, } else { s->s_mode =3D mode; snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev); + shrinker_debugfs_rename(&s->s_shrink, "sb-%s:%s", + fs_type->name, s->s_id); sb_set_blocksize(s, block_size(bdev)); error =3D fill_super(s, data, flags & SB_SILENT ? 1 : 0); if (error) { diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index bad67455215f..a3663d201f64 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -2430,7 +2430,7 @@ static int __init ubifs_init(void) if (!ubifs_inode_slab) return -ENOMEM; =20 - err =3D register_shrinker(&ubifs_shrinker_info); + err =3D register_shrinker(&ubifs_shrinker_info, "ubifs"); if (err) goto out_slab; =20 diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index e1afb9e503e1..5645e92df0c9 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -1986,7 +1986,7 @@ xfs_alloc_buftarg( btp->bt_shrinker.scan_objects =3D xfs_buftarg_shrink_scan; btp->bt_shrinker.seeks =3D DEFAULT_SEEKS; btp->bt_shrinker.flags =3D SHRINKER_NUMA_AWARE; - if (register_shrinker(&btp->bt_shrinker)) + if (register_shrinker(&btp->bt_shrinker, "xfs_buf")) goto error_pcpu; return btp; =20 diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c index bffd6eb0b298..d0c4e74ff763 100644 --- a/fs/xfs/xfs_icache.c +++ b/fs/xfs/xfs_icache.c @@ -2198,5 +2198,5 @@ xfs_inodegc_register_shrinker( shrink->flags =3D SHRINKER_NONSLAB; shrink->batch =3D XFS_INODEGC_SHRINKER_BATCH; =20 - return register_shrinker(shrink); + return register_shrinker(shrink, "xfs_inodegc"); } diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c index f165d1a3de1d..93ded9e81f49 100644 --- a/fs/xfs/xfs_qm.c +++ b/fs/xfs/xfs_qm.c @@ -686,7 +686,7 @@ xfs_qm_init_quotainfo( qinf->qi_shrinker.seeks =3D DEFAULT_SEEKS; qinf->qi_shrinker.flags =3D SHRINKER_NUMA_AWARE; =20 - error =3D register_shrinker(&qinf->qi_shrinker); + error =3D register_shrinker(&qinf->qi_shrinker, "xfs_qm"); if (error) goto out_free_inos; =20 diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h index 2ced8149c513..64416f3e0a1f 100644 --- a/include/linux/shrinker.h +++ b/include/linux/shrinker.h @@ -75,6 +75,7 @@ struct shrinker { #endif #ifdef CONFIG_SHRINKER_DEBUG int debugfs_id; + const char *name; struct dentry *debugfs_entry; #endif /* objs pending delete, per node */ @@ -92,9 +93,9 @@ struct shrinker { */ #define SHRINKER_NONSLAB (1 << 3) =20 -extern int prealloc_shrinker(struct shrinker *shrinker); +extern int prealloc_shrinker(struct shrinker *shrinker, const char *fmt, .= ..); extern void register_shrinker_prepared(struct shrinker *shrinker); -extern int register_shrinker(struct shrinker *shrinker); +extern int register_shrinker(struct shrinker *shrinker, const char *fmt, .= ..); extern void unregister_shrinker(struct shrinker *shrinker); extern void free_prealloced_shrinker(struct shrinker *shrinker); extern void synchronize_shrinkers(void); @@ -102,6 +103,8 @@ extern void synchronize_shrinkers(void); #ifdef CONFIG_SHRINKER_DEBUG extern int shrinker_debugfs_add(struct shrinker *shrinker); extern void shrinker_debugfs_remove(struct shrinker *shrinker); +extern int shrinker_debugfs_rename(struct shrinker *shrinker, + const char *fmt, ...); #else /* CONFIG_SHRINKER_DEBUG */ static inline int shrinker_debugfs_add(struct shrinker *shrinker) { @@ -110,5 +113,10 @@ static inline int shrinker_debugfs_add(struct shrinker= *shrinker) static inline void shrinker_debugfs_remove(struct shrinker *shrinker) { } +static inline int shrinker_debugfs_rename(struct shrinker *shrinker, + const char *fmt, ...) +{ + return 0; +} #endif /* CONFIG_SHRINKER_DEBUG */ #endif /* _LINUX_SHRINKER_H */ diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 5c587e00811c..b4c66916bea9 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -4978,7 +4978,7 @@ static void __init kfree_rcu_batch_init(void) INIT_DELAYED_WORK(&krcp->page_cache_work, fill_page_cache_func); krcp->initialized =3D true; } - if (register_shrinker(&kfree_rcu_shrinker)) + if (register_shrinker(&kfree_rcu_shrinker, "kfree_rcu")) pr_err("Failed to register kfree_rcu() shrinker!\n"); } =20 diff --git a/mm/huge_memory.c b/mm/huge_memory.c index fa6a1623976a..a40df19c0e38 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -423,10 +423,10 @@ static int __init hugepage_init(void) if (err) goto err_slab; =20 - err =3D register_shrinker(&huge_zero_page_shrinker); + err =3D register_shrinker(&huge_zero_page_shrinker, "thp_zero"); if (err) goto err_hzp_shrinker; - err =3D register_shrinker(&deferred_split_shrinker); + err =3D register_shrinker(&deferred_split_shrinker, "thp_deferred_split"); if (err) goto err_split_shrinker; =20 diff --git a/mm/shrinker_debug.c b/mm/shrinker_debug.c index fd1f805a581a..28b1c1ab60ef 100644 --- a/mm/shrinker_debug.c +++ b/mm/shrinker_debug.c @@ -104,7 +104,7 @@ DEFINE_SHOW_ATTRIBUTE(shrinker_debugfs_count); int shrinker_debugfs_add(struct shrinker *shrinker) { struct dentry *entry; - char buf[16]; + char buf[128]; int id; =20 lockdep_assert_held(&shrinker_rwsem); @@ -118,7 +118,7 @@ int shrinker_debugfs_add(struct shrinker *shrinker) return id; shrinker->debugfs_id =3D id; =20 - snprintf(buf, sizeof(buf), "%d", id); + snprintf(buf, sizeof(buf), "%s-%d", shrinker->name, id); =20 /* create debugfs entry */ entry =3D debugfs_create_dir(buf, shrinker_debugfs_root); @@ -133,10 +133,51 @@ int shrinker_debugfs_add(struct shrinker *shrinker) return 0; } =20 +int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ..= .) +{ + struct dentry *entry; + char buf[128]; + const char *old; + va_list ap; + int ret =3D 0; + + down_write(&shrinker_rwsem); + + old =3D shrinker->name; + + va_start(ap, fmt); + shrinker->name =3D kvasprintf_const(GFP_KERNEL, fmt, ap); + va_end(ap); + if (!shrinker->name) { + shrinker->name =3D old; + ret =3D -ENOMEM; + } else if (shrinker->debugfs_entry) { + snprintf(buf, sizeof(buf), "%s-%d", shrinker->name, + shrinker->debugfs_id); + + entry =3D debugfs_rename(shrinker_debugfs_root, + shrinker->debugfs_entry, + shrinker_debugfs_root, buf); + if (IS_ERR(entry)) + ret =3D PTR_ERR(entry); + else + shrinker->debugfs_entry =3D entry; + + kfree_const(old); + } + + up_write(&shrinker_rwsem); + + return ret; +} +EXPORT_SYMBOL(shrinker_debugfs_rename); + void shrinker_debugfs_remove(struct shrinker *shrinker) { lockdep_assert_held(&shrinker_rwsem); =20 + kfree_const(shrinker->name); + if (!shrinker->debugfs_entry) return; =20 diff --git a/mm/vmscan.c b/mm/vmscan.c index 024f7056b98c..42bae0fd0442 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -613,7 +613,7 @@ static unsigned long lruvec_lru_size(struct lruvec *lru= vec, enum lru_list lru, /* * Add a shrinker callback to be called from the vm. */ -int prealloc_shrinker(struct shrinker *shrinker) +static int __prealloc_shrinker(struct shrinker *shrinker) { unsigned int size; int err; @@ -637,8 +637,36 @@ int prealloc_shrinker(struct shrinker *shrinker) return 0; } =20 +#ifdef CONFIG_SHRINKER_DEBUG +int prealloc_shrinker(struct shrinker *shrinker, const char *fmt, ...) +{ + va_list ap; + int err; + + va_start(ap, fmt); + shrinker->name =3D kvasprintf_const(GFP_KERNEL, fmt, ap); + va_end(ap); + if (!shrinker->name) + return -ENOMEM; + + err =3D __prealloc_shrinker(shrinker); + if (err) + kfree_const(shrinker->name); + + return err; +} +#else +int prealloc_shrinker(struct shrinker *shrinker, const char *fmt, ...) +{ + return __prealloc_shrinker(shrinker); +} +#endif + void free_prealloced_shrinker(struct shrinker *shrinker) { +#ifdef CONFIG_SHRINKER_DEBUG + kfree_const(shrinker->name); +#endif if (shrinker->flags & SHRINKER_MEMCG_AWARE) { down_write(&shrinker_rwsem); unregister_memcg_shrinker(shrinker); @@ -659,15 +687,39 @@ void register_shrinker_prepared(struct shrinker *shri= nker) up_write(&shrinker_rwsem); } =20 -int register_shrinker(struct shrinker *shrinker) +static int __register_shrinker(struct shrinker *shrinker) { - int err =3D prealloc_shrinker(shrinker); + int err =3D __prealloc_shrinker(shrinker); =20 if (err) return err; register_shrinker_prepared(shrinker); return 0; } + +#ifdef CONFIG_SHRINKER_DEBUG +int register_shrinker(struct shrinker *shrinker, const char *fmt, ...) +{ + va_list ap; + int err; + + va_start(ap, fmt); + shrinker->name =3D kvasprintf_const(GFP_KERNEL, fmt, ap); + va_end(ap); + if (!shrinker->name) + return -ENOMEM; + + err =3D __register_shrinker(shrinker); + if (err) + kfree_const(shrinker->name); + return err; +} +#else +int register_shrinker(struct shrinker *shrinker, const char *fmt, ...) +{ + return __register_shrinker(shrinker); +} +#endif EXPORT_SYMBOL(register_shrinker); =20 /* diff --git a/mm/workingset.c b/mm/workingset.c index 592569a8974c..840986179cf3 100644 --- a/mm/workingset.c +++ b/mm/workingset.c @@ -625,7 +625,7 @@ static int __init workingset_init(void) pr_info("workingset: timestamp_bits=3D%d max_order=3D%d bucket_order=3D%u= \n", timestamp_bits, max_order, bucket_order); =20 - ret =3D prealloc_shrinker(&workingset_shadow_shrinker); + ret =3D prealloc_shrinker(&workingset_shadow_shrinker, "shadow"); if (ret) goto err; ret =3D __list_lru_init(&shadow_nodes, true, &shadow_nodes_key, diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 9152fbde33b5..a19de176f604 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -2188,7 +2188,7 @@ static int zs_register_shrinker(struct zs_pool *pool) pool->shrinker.batch =3D 0; pool->shrinker.seeks =3D DEFAULT_SEEKS; =20 - return register_shrinker(&pool->shrinker); + return register_shrinker(&pool->shrinker, "zspool"); } =20 /** diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c index 682fcd24bf43..a29742a9c3f1 100644 --- a/net/sunrpc/auth.c +++ b/net/sunrpc/auth.c @@ -874,7 +874,7 @@ int __init rpcauth_init_module(void) err =3D rpc_init_authunix(); if (err < 0) goto out1; - err =3D register_shrinker(&rpc_cred_shrinker); + err =3D register_shrinker(&rpc_cred_shrinker, "rpc_cred"); if (err < 0) goto out2; return 0; --=20 2.35.3 From nobody Mon Jun 15 00:03:25 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E08EC433EF for ; Mon, 9 May 2022 18:38:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240277AbiEISml (ORCPT ); Mon, 9 May 2022 14:42:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240263AbiEISmg (ORCPT ); Mon, 9 May 2022 14:42:36 -0400 Received: from out0.migadu.com (out0.migadu.com [94.23.1.103]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC08726084D for ; Mon, 9 May 2022 11:38:41 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1652121520; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7n7dZu7Y2U7vRxgiVDuS2aKmDH89wQvt+0LixtzJNwc=; b=X/nmv/5QYZdTAzGxptAD4HPoB18DvwQnGzxs6tocRwwWGHUwAf0dXoJv6HV36AZ2MRiLg5 delJvvKPQNEMK2y3q5GqoDzm/YJdiqd6IE5g7Y5r8IbHt0MsYBn15MdfhXHUYubKeL5k/W ezRjg1syyJ3GqACNqrZC1NSHYzwYSOA= From: Roman Gushchin To: Andrew Morton , linux-mm@kvack.org Cc: Dave Chinner , linux-kernel@vger.kernel.org, Kent Overstreet , Hillf Danton , Christophe JAILLET , Roman Gushchin Subject: [PATCH v3 4/6] mm: docs: document shrinker debugfs Date: Mon, 9 May 2022 11:38:18 -0700 Message-Id: <20220509183820.573666-5-roman.gushchin@linux.dev> In-Reply-To: <20220509183820.573666-1-roman.gushchin@linux.dev> References: <20220509183820.573666-1-roman.gushchin@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Add a document describing the shrinker debugfs interface. Signed-off-by: Roman Gushchin --- Documentation/admin-guide/mm/index.rst | 1 + .../admin-guide/mm/shrinker_debugfs.rst | 100 ++++++++++++++++++ 2 files changed, 101 insertions(+) create mode 100644 Documentation/admin-guide/mm/shrinker_debugfs.rst diff --git a/Documentation/admin-guide/mm/index.rst b/Documentation/admin-g= uide/mm/index.rst index c21b5823f126..1bd11118dfb1 100644 --- a/Documentation/admin-guide/mm/index.rst +++ b/Documentation/admin-guide/mm/index.rst @@ -36,6 +36,7 @@ the Linux memory management. numa_memory_policy numaperf pagemap + shrinker_debugfs soft-dirty swap_numa transhuge diff --git a/Documentation/admin-guide/mm/shrinker_debugfs.rst b/Documentat= ion/admin-guide/mm/shrinker_debugfs.rst new file mode 100644 index 000000000000..6783f8190e63 --- /dev/null +++ b/Documentation/admin-guide/mm/shrinker_debugfs.rst @@ -0,0 +1,100 @@ +.. _shrinker_debugfs: + +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D +Shrinker Debugfs Interface +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D + +Shrinker debugfs interface provides a visibility into the kernel memory +shrinkers subsystem and allows to get information about individual shrinke= rs. + +For each shrinker registered in the system a directory in **/shri= nker/** +is created. The directory's name is composed from the shrinker's name and = an +unique id: e.g. *kfree_rcu-0* or *sb-xfs:vda1-36*. + +Each shrinker directory contains the **count** file, which allows to trigg= er +the *count_objects()* callback for each memcg and numa node (if applicable= ). + +Usage: +------ + +1. *List registered shrinkers* + + :: + + $ cd /sys/kernel/debug/shrinker/ + $ ls + dqcache-16 sb-hugetlbfs-17 sb-rootfs-2 sb-tmpfs-50 + kfree_rcu-0 sb-hugetlbfs-33 sb-securityfs-6 sb-tracefs-13 + sb-aio-20 sb-iomem-12 sb-selinuxfs-22 sb-xfs:vda1-36 + sb-anon_inodefs-15 sb-mqueue-21 sb-sockfs-8 sb-zsmalloc-19 + sb-bdev-3 sb-nsfs-4 sb-sysfs-26 shadow-18 + sb-bpf-32 sb-pipefs-14 sb-tmpfs-1 thp_deferred_spl= it-10 + sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-27 thp_zero-9 + sb-cgroup2-30 sb-proc-39 sb-tmpfs-29 xfs_buf-37 + sb-configfs-23 sb-proc-41 sb-tmpfs-35 xfs_inodegc-38 + sb-dax-11 sb-proc-45 sb-tmpfs-40 zspool-34 + sb-debugfs-7 sb-proc-46 sb-tmpfs-42 + sb-devpts-28 sb-proc-47 sb-tmpfs-43 + sb-devtmpfs-5 sb-pstore-31 sb-tmpfs-44 + +2. *Get information about a specific shrinker* + + :: + + $ cd sb-btrfs\:vda2-24/ + $ ls + count + +3. *Count objects* + + Each line in the output has the following format:: + + = ... + = ... + ... + + If there are no objects on all numa nodes, a line is omitted. If there + are no objects at all, the output might be empty. + :: + + $ cat count + 1 224 2 + 21 98 0 + 55 818 10 + 2367 2 0 + 2401 30 0 + 225 13 0 + 599 35 0 + 939 124 0 + 1041 3 0 + 1075 1 0 + 1109 1 0 + 1279 60 0 + 1313 7 0 + 1347 39 0 + 1381 3 0 + 1449 14 0 + 1483 63 0 + 1517 53 0 + 1551 6 0 + 1585 1 0 + 1619 6 0 + 1653 40 0 + 1687 11 0 + 1721 8 0 + 1755 4 0 + 1789 52 0 + 1823 888 0 + 1857 1 0 + 1925 2 0 + 1959 32 0 + 2027 22 0 + 2061 9 0 + 2469 799 0 + 2537 861 0 + 2639 1 0 + 2707 70 0 + 2775 4 0 + 2877 84 0 + 293 1 0 + 735 8 0 --=20 2.35.3 From nobody Mon Jun 15 00:03:25 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 042BDC433F5 for ; Mon, 9 May 2022 18:38:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240282AbiEISmq (ORCPT ); Mon, 9 May 2022 14:42:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42340 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240272AbiEISmj (ORCPT ); Mon, 9 May 2022 14:42:39 -0400 Received: from out0.migadu.com (out0.migadu.com [IPv6:2001:41d0:2:267::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50818260867 for ; Mon, 9 May 2022 11:38:44 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1652121522; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2z4am8efPkBHe5K6q2zk3FpEuHSEHOPmz0WCK0OizBQ=; b=W7wTrLUT6pcfa+GNzHQSJr6RwTrBgKY7pSyQYtBPdqz4ksSV8Yr5fAs3rpz4B97+6bbg8W brZ0u/I84OUgoI1tSOEmCIe4x2IKx43Kjlhv9+79j36wGsJ37VymFjCiOnOH3Pf3eMJl2a dY72NIvHL5sz3BH0qpSs/suYcaU2khM= From: Roman Gushchin To: Andrew Morton , linux-mm@kvack.org Cc: Dave Chinner , linux-kernel@vger.kernel.org, Kent Overstreet , Hillf Danton , Christophe JAILLET , Roman Gushchin Subject: [PATCH v3 5/6] tools: add memcg_shrinker.py Date: Mon, 9 May 2022 11:38:19 -0700 Message-Id: <20220509183820.573666-6-roman.gushchin@linux.dev> In-Reply-To: <20220509183820.573666-1-roman.gushchin@linux.dev> References: <20220509183820.573666-1-roman.gushchin@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Add a simple tool which prints a sorted list of shrinker lists in the following format: (number of objects, shrinker name, cgroup). Example: $ ./memcg_shrinker.py -n 10 2090 sb-sysfs-26 /sys/fs/cgroup/system.slice 1809 sb-sysfs-26 /sys/fs/cgroup/system.slice/systemd-udevd.s= ervice 1044 sb-btrfs:vda2-24 /sys/fs/cgroup/system.slice/system-dbus\x2d= :1.3\... 861 sb-btrfs:vda2-24 /sys/fs/cgroup/system.slice/system-dbus\x2d= :1.3\... 804 sb-btrfs:vda2-24 /sys/fs/cgroup/system.slice 643 sb-btrfs:vda2-24 /sys/fs/cgroup/system.slice/firewalld.servi= ce 616 sb-cgroup2-30 /sys/fs/cgroup/init.scope 275 sb-sysfs-26 / 238 sb-proc-25 /sys/fs/cgroup/system.slice/systemd-journal= d.service 225 sb-proc-25 /sys/fs/cgroup/system.slice/abrtd.service Signed-off-by: Roman Gushchin --- tools/cgroup/memcg_shrinker.py | 71 ++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100755 tools/cgroup/memcg_shrinker.py diff --git a/tools/cgroup/memcg_shrinker.py b/tools/cgroup/memcg_shrinker.py new file mode 100755 index 000000000000..706ab27666a4 --- /dev/null +++ b/tools/cgroup/memcg_shrinker.py @@ -0,0 +1,71 @@ +#!/usr/bin/env python3 +# +# Copyright (C) 2022 Roman Gushchin +# Copyright (C) 2022 Meta + +import os +import argparse +import sys + + +def scan_cgroups(cgroup_root): + cgroups =3D {} + + for root, subdirs, _ in os.walk(cgroup_root): + for cgroup in subdirs: + path =3D os.path.join(root, cgroup) + ino =3D os.stat(path).st_ino + cgroups[ino] =3D path + + # (memcg ino, path) + return cgroups + + +def scan_shrinkers(shrinker_debugfs): + shrinkers =3D [] + + for root, subdirs, _ in os.walk(shrinker_debugfs): + for shrinker in subdirs: + count_path =3D os.path.join(root, shrinker, "count") + with open(count_path) as f: + for line in f.readlines(): + items =3D line.split(' ') + ino =3D int(items[0]) + # (count, shrinker, memcg ino) + shrinkers.append((int(items[1]), shrinker, ino)) + return shrinkers + + +def main(): + parser =3D argparse.ArgumentParser(description=3D'Display biggest shri= nkers') + parser.add_argument('-n', '--lines', type=3Dint, help=3D'Number of lin= es to print') + + args =3D parser.parse_args() + + cgroups =3D scan_cgroups("/sys/fs/cgroup/") + shrinkers =3D scan_shrinkers("/sys/kernel/debug/shrinker/") + shrinkers =3D sorted(shrinkers, reverse =3D True, key =3D lambda x: x[= 0]) + + n =3D 0 + for s in shrinkers: + count, name, ino =3D (s[0], s[1], s[2]) + if count =3D=3D 0: + break + + if ino =3D=3D 0 or ino =3D=3D 1: + cg =3D "/" + else: + try: + cg =3D cgroups[ino] + except KeyError: + cg =3D "unknown (%d)" % ino + + print("%-8s %-20s %s" % (count, name, cg)) + + n +=3D 1 + if args.lines and n >=3D args.lines: + break + + +if __name__ =3D=3D '__main__': + main() --=20 2.35.3 From nobody Mon Jun 15 00:03:25 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 47576C433EF for ; Mon, 9 May 2022 18:38:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240288AbiEISmu (ORCPT ); Mon, 9 May 2022 14:42:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42472 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240216AbiEISmk (ORCPT ); Mon, 9 May 2022 14:42:40 -0400 Received: from out0.migadu.com (out0.migadu.com [94.23.1.103]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5232926086B for ; Mon, 9 May 2022 11:38:46 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1652121524; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=G0nsxyzGb1i11ycGLFmpikTl6TwBBRGWt6VA6PTf/VI=; b=MGMq29EFa8FQSOBa6oumVjlBpR2OcRgE4ObbYzl2jTIkeEugSFzKva5kAUVdBmBYGHXCKH 5L0j+wlTWkeAq93clx7+ie2Mkn/7ttrWEW2I4TScScRoM/uIVtxtPaOmdKG/4PH2p6xyL8 eoQgEswaQWIZITazBVUeekuPoHBqq/8= From: Roman Gushchin To: Andrew Morton , linux-mm@kvack.org Cc: Dave Chinner , linux-kernel@vger.kernel.org, Kent Overstreet , Hillf Danton , Christophe JAILLET , Roman Gushchin Subject: [PATCH v3 6/6] mm: shrinkers: add scan interface for shrinker debugfs Date: Mon, 9 May 2022 11:38:20 -0700 Message-Id: <20220509183820.573666-7-roman.gushchin@linux.dev> In-Reply-To: <20220509183820.573666-1-roman.gushchin@linux.dev> References: <20220509183820.573666-1-roman.gushchin@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Add a scan interface which allows to trigger scanning of a particular shrinker and specify memcg and numa node. It's useful for testing, debugging and profiling of a specific scan_objects() callback. Unlike alternatives (creating a real memory pressure and dropping caches via /proc/sys/vm/drop_caches) this interface allows to interact with only one shrinker at once. Also, if a shrinker is misreporting the number of objects (as some do), it doesn't affect scanning. Signed-off-by: Roman Gushchin --- .../admin-guide/mm/shrinker_debugfs.rst | 39 +++++++++- mm/shrinker_debug.c | 73 +++++++++++++++++++ 2 files changed, 108 insertions(+), 4 deletions(-) diff --git a/Documentation/admin-guide/mm/shrinker_debugfs.rst b/Documentat= ion/admin-guide/mm/shrinker_debugfs.rst index 6783f8190e63..8fecf81d60ee 100644 --- a/Documentation/admin-guide/mm/shrinker_debugfs.rst +++ b/Documentation/admin-guide/mm/shrinker_debugfs.rst @@ -5,14 +5,16 @@ Shrinker Debugfs Interface =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D =20 Shrinker debugfs interface provides a visibility into the kernel memory -shrinkers subsystem and allows to get information about individual shrinke= rs. +shrinkers subsystem and allows to get information about individual shrinke= rs +and interact with them. =20 For each shrinker registered in the system a directory in **/shri= nker/** is created. The directory's name is composed from the shrinker's name and = an unique id: e.g. *kfree_rcu-0* or *sb-xfs:vda1-36*. =20 -Each shrinker directory contains the **count** file, which allows to trigg= er -the *count_objects()* callback for each memcg and numa node (if applicable= ). +Each shrinker directory contains **count** and **scan** files, which allow= to +trigger *count_objects()* and *scan_objects()* callbacks for each memcg and +numa node (if applicable). =20 Usage: ------ @@ -43,7 +45,7 @@ Usage: =20 $ cd sb-btrfs\:vda2-24/ $ ls - count + count scan =20 3. *Count objects* =20 @@ -98,3 +100,32 @@ Usage: 2877 84 0 293 1 0 735 8 0 + +4. *Scan objects* + + The expected input format:: + + + + For a non-memcg-aware shrinker or on a system with no memory + cgrups **0** should be passed as cgroup id. + :: + + $ cd /sys/kernel/debug/shrinker/ + $ cd sb-btrfs\:vda2-24/ + + $ cat count | head -n 5 + 1 212 0 + 21 97 0 + 55 802 5 + 2367 2 0 + 225 13 0 + + $ echo "55 0 200" > scan + + $ cat count | head -n 5 + 1 212 0 + 21 96 0 + 55 752 5 + 2367 2 0 + 225 13 0 diff --git a/mm/shrinker_debug.c b/mm/shrinker_debug.c index 28b1c1ab60ef..8f67fef5a643 100644 --- a/mm/shrinker_debug.c +++ b/mm/shrinker_debug.c @@ -101,6 +101,77 @@ static int shrinker_debugfs_count_show(struct seq_file= *m, void *v) } DEFINE_SHOW_ATTRIBUTE(shrinker_debugfs_count); =20 +static int shrinker_debugfs_scan_open(struct inode *inode, struct file *fi= le) +{ + file->private_data =3D inode->i_private; + return nonseekable_open(inode, file); +} + +static ssize_t shrinker_debugfs_scan_write(struct file *file, + const char __user *buf, + size_t size, loff_t *pos) +{ + struct shrinker *shrinker =3D (struct shrinker *)file->private_data; + unsigned long nr_to_scan =3D 0, ino; + struct shrink_control sc =3D { + .gfp_mask =3D GFP_KERNEL, + }; + struct mem_cgroup *memcg =3D NULL; + int nid; + char kbuf[72]; + int read_len =3D size < (sizeof(kbuf) - 1) ? size : (sizeof(kbuf) - 1); + ssize_t ret; + + if (copy_from_user(kbuf, buf, read_len)) + return -EFAULT; + kbuf[read_len] =3D '\0'; + + if (sscanf(kbuf, "%lu %d %lu", &ino, &nid, &nr_to_scan) < 2) + return -EINVAL; + + if (nid < 0 || nid >=3D nr_node_ids) + return -EINVAL; + + if (shrinker->flags & SHRINKER_MEMCG_AWARE) { + memcg =3D mem_cgroup_get_from_ino(ino); + if (!memcg || IS_ERR(memcg)) + return -ENOENT; + + if (!mem_cgroup_online(memcg)) { + mem_cgroup_put(memcg); + return -ENOENT; + } + } else { + if (ino !=3D 0) + return -EINVAL; + memcg =3D NULL; + } + + ret =3D down_read_killable(&shrinker_rwsem); + if (ret) { + mem_cgroup_put(memcg); + return ret; + } + + sc.nid =3D nid; + sc.memcg =3D memcg; + sc.nr_to_scan =3D nr_to_scan; + sc.nr_scanned =3D nr_to_scan; + + shrinker->scan_objects(shrinker, &sc); + + up_read(&shrinker_rwsem); + mem_cgroup_put(memcg); + + return ret ? ret : size; +} + +static const struct file_operations shrinker_debugfs_scan_fops =3D { + .owner =3D THIS_MODULE, + .open =3D shrinker_debugfs_scan_open, + .write =3D shrinker_debugfs_scan_write, +}; + int shrinker_debugfs_add(struct shrinker *shrinker) { struct dentry *entry; @@ -130,6 +201,8 @@ int shrinker_debugfs_add(struct shrinker *shrinker) =20 debugfs_create_file("count", 0220, entry, shrinker, &shrinker_debugfs_count_fops); + debugfs_create_file("scan", 0440, entry, shrinker, + &shrinker_debugfs_scan_fops); return 0; } =20 --=20 2.35.3