From nobody Wed Apr 29 03:20:59 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 8EDD0C433EF for ; Tue, 24 May 2022 10:36:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236267AbiEXKgy (ORCPT ); Tue, 24 May 2022 06:36:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42568 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236044AbiEXKgt (ORCPT ); Tue, 24 May 2022 06:36:49 -0400 Received: from mail-pg1-x52f.google.com (mail-pg1-x52f.google.com [IPv6:2607:f8b0:4864:20::52f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 476DAFD1C for ; Tue, 24 May 2022 03:36:48 -0700 (PDT) Received: by mail-pg1-x52f.google.com with SMTP id 137so16003879pgb.5 for ; Tue, 24 May 2022 03:36:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=Mv0h03Fi/OtxPp/Z+fPoItRmuRgY3cwaQPU9funRX9c=; b=XSkF/bmPvGekW75aBNlxtn4mVjVNuZkS8BypyCMs1G5idGF4Ty3XbFkec8vlHBZMaj zZwD2LVcBdYOOHEDFY9XAoWlv78XpR6SeHp/n21hGalRs7qtlO8pDMhAQzN6/Sm7kUfI aiBO9h/VWkiDCNG8a5iZDWtmuNe/raMvjMRrCW9B4u8ZWES3W7Fdd2QnMvwP02HDxhRl yR+gXercw+VgwdzFpA171XoYDBJ4URP3bB0ZcxwNifVs6zwanO703O+XCetzwpoBPHl5 1sxVk7U579O7sNBv8XzyWH3IHvyjibFJeXc8o4euBduT94QIJ6oZN+m0+ssKCU/X9GmZ j1jg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=Mv0h03Fi/OtxPp/Z+fPoItRmuRgY3cwaQPU9funRX9c=; b=AXD2rOdWpzRiBbJX2QnIdYsBU1truKRPSl07infzDFKALO7oiYzYx7NWrqSB1q54TU 09kE9HnKJFKVMm9ZwCe/aMxPmhmY1VFwCgF5j8N+ZhRnCK4hagEOtxYX8jpQyGZJoIax hpqR7WjwLWEUc9Mwhl1OB6CtVMMtOK905gpnZWp79FYsS5gbIJwr0NXrdH1RLaQ9HIvG mBfpIb7YmsccxvGgc6+C7KmO035/jLR8qyWWjVosEqjISkO7yg7JzA5IY0UKF5R2xOgG gJE0lsV7V4YJwqne6+IBoqEAyG9XczZS86CTrwYzASXiLgJctWVONRN2aiiJaX1+/+TG lkrA== X-Gm-Message-State: AOAM532r93TwweDaesiFTgt/A1ueu34sfff48a/PcEOIs1Q6883TKja1 /AzvcwVXLei7zXNmEvOhank1eQ== X-Google-Smtp-Source: ABdhPJzU0XpiMdHt9AZg3iIPm1ofoXx4H5Mz44HKUELtKJUbPAnWeRAYPyeFGF6qI+8tBZMmdL6dOA== X-Received: by 2002:a63:fc08:0:b0:3f9:e159:b114 with SMTP id j8-20020a63fc08000000b003f9e159b114mr14550018pgi.526.1653388607832; Tue, 24 May 2022 03:36:47 -0700 (PDT) Received: from R911R1VA-1UT.bytedance.net ([139.177.225.245]) by smtp.gmail.com with ESMTPSA id j12-20020a170903024c00b00161823de53csm6913010plh.282.2022.05.24.03.36.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 24 May 2022 03:36:47 -0700 (PDT) From: hezhongkun To: hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, lizefan.x@bytedance.com, Hezhongkun Subject: [PATCH] mm: memcontrol: add the mempolicy interface for cgroup v2. Date: Tue, 24 May 2022 18:36:38 +0800 Message-Id: <20220524103638.473-1-hezhongkun.hzk@bytedance.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Hezhongkun Mempolicy is difficult to use because it is set in-process via a system call. We want to make it easier to use mempolicy in cgroups, so that we can control low-priority cgroups to allocate memory in specified nodes. So this patch want to adds the mempolicy interface. the mempolicy priority of memcgroup is higher than the priority of task. The order of getting the policy is, memcgroup->policy,task->policy or vma policy, default policy. memcgroup's policy is owned by itself, so descendants will not inherit it. Signed-off-by: Hezhongkun Reported-by: kernel test robot Reported-by: kernel test robot --- include/linux/memcontrol.h | 1 + mm/memcontrol.c | 42 ++++++++++++++++++++++++++++++++++++++ mm/mempolicy.c | 30 ++++++++++++++++++++++----- 3 files changed, 68 insertions(+), 5 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 89b14729d59f..2261eeb6100c 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -343,6 +343,7 @@ struct mem_cgroup { #ifdef CONFIG_TRANSPARENT_HUGEPAGE struct deferred_split deferred_split_queue; #endif + struct mempolicy *mempolicy; =20 struct mem_cgroup_per_node *nodeinfo[]; }; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 598fece89e2b..38108fd4df64 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6332,6 +6332,42 @@ static int memory_numa_stat_show(struct seq_file *m,= void *v) =20 return 0; } + +static int memory_policy_show(struct seq_file *m, void *v) +{ + char buffer[64]; + struct mempolicy *mpol =3D mem_cgroup_from_seq(m)->mempolicy; + + memset(buffer, 0, sizeof(buffer)); + + if (!mpol || mpol->mode =3D=3D MPOL_DEFAULT) + return 0; + + mpol_to_str(buffer, sizeof(buffer), mpol); + seq_printf(m, buffer); + seq_putc(m, '\n'); + return 0; +} + +static ssize_t memory_policy_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + int err =3D 1; + struct mempolicy *mpol, *old; + struct mem_cgroup *memcg =3D mem_cgroup_from_css(of_css(of)); + + old =3D memcg->mempolicy; + buf =3D strstrip(buf); + err =3D mpol_parse_str(buf, &mpol); + + if (err) + goto out; + mpol_put(old); + memcg->mempolicy =3D mpol; +out: + return nbytes; +} + #endif =20 static int memory_oom_group_show(struct seq_file *m, void *v) @@ -6416,6 +6452,12 @@ static struct cftype memory_files[] =3D { .name =3D "numa_stat", .seq_show =3D memory_numa_stat_show, }, + { + .name =3D "policy", + .flags =3D CFTYPE_NOT_ON_ROOT, + .seq_show =3D memory_policy_show, + .write =3D memory_policy_write, + }, #endif { .name =3D "oom.group", diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 8c74107a2b15..5153b046f8c3 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -176,6 +176,16 @@ struct mempolicy *get_task_policy(struct task_struct *= p) return &default_policy; } =20 +struct mempolicy *get_cgrp_or_task_policy(struct task_struct *p) +{ + struct mempolicy *pol; + struct mem_cgroup *memcg =3D mem_cgroup_from_task(p); + + pol =3D (memcg && memcg->mempolicy) ? memcg->mempolicy : get_task_policy(= p); + return pol; +} + + static const struct mempolicy_operations { int (*create)(struct mempolicy *pol, const nodemask_t *nodes); void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes); @@ -1782,6 +1792,16 @@ static struct mempolicy *get_vma_policy(struct vm_ar= ea_struct *vma, return pol; } =20 +static struct mempolicy *get_cgrp_or_vma_policy(struct vm_area_struct *vma, + unsigned long addr) +{ + struct mempolicy *pol; + struct mem_cgroup *memcg =3D mem_cgroup_from_task(current); + + pol =3D (memcg && memcg->mempolicy) ? memcg->mempolicy : get_vma_policy(v= ma, addr); + return pol; +} + bool vma_policy_mof(struct vm_area_struct *vma) { struct mempolicy *pol; @@ -1896,7 +1916,7 @@ unsigned int mempolicy_slab_node(void) if (!in_task()) return node; =20 - policy =3D current->mempolicy; + policy =3D get_cgrp_or_task_policy(current); if (!policy) return node; =20 @@ -2005,7 +2025,7 @@ int huge_node(struct vm_area_struct *vma, unsigned lo= ng addr, gfp_t gfp_flags, int nid; int mode; =20 - *mpol =3D get_vma_policy(vma, addr); + *mpol =3D get_cgrp_or_vma_policy(vma, addr); *nodemask =3D NULL; mode =3D (*mpol)->mode; =20 @@ -2158,7 +2178,7 @@ struct page *alloc_pages_vma(gfp_t gfp, int order, st= ruct vm_area_struct *vma, int preferred_nid; nodemask_t *nmask; =20 - pol =3D get_vma_policy(vma, addr); + pol =3D get_cgrp_or_vma_policy(vma, addr); =20 if (pol->mode =3D=3D MPOL_INTERLEAVE) { unsigned nid; @@ -2257,7 +2277,7 @@ struct page *alloc_pages(gfp_t gfp, unsigned order) struct page *page; =20 if (!in_interrupt() && !(gfp & __GFP_THISNODE)) - pol =3D get_task_policy(current); + pol =3D get_cgrp_or_task_policy(current); =20 /* * No reference counting needed for current->mempolicy @@ -2562,7 +2582,7 @@ int mpol_misplaced(struct page *page, struct vm_area_= struct *vma, unsigned long int polnid =3D NUMA_NO_NODE; int ret =3D NUMA_NO_NODE; =20 - pol =3D get_vma_policy(vma, addr); + pol =3D get_cgrp_or_vma_policy(vma, addr); if (!(pol->flags & MPOL_F_MOF)) goto out; =20 --=20 2.17.1