From nobody Sat Apr 11 20:56:33 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 66BA9C19F2A for ; Mon, 8 Aug 2022 02:42:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244065AbiHHCmo (ORCPT ); Sun, 7 Aug 2022 22:42:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242235AbiHHClk (ORCPT ); Sun, 7 Aug 2022 22:41:40 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0B7E125D8 for ; Sun, 7 Aug 2022 19:41:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=sneZ41lYORveEGJd86wLRINVdrJyNjdlMYzBcdpxZVM=; b=gHsZmUmooiEPQn2wHoC+85cXvp uUArEgvwkwTMO/rXNRp0gPoodsCYZIIJnFcz75pPW3q8m5am8CL0NhvgxKYYAWrSAUeC73Z/lPkPs h4I44dOOHdLqJhxSlBifUdptWyIeU2ZxgB6iQ2w6KaPpsCDck6HhMij6kmyazjOnSEUnr6L1jLqJ9 IQSY+w7Z78SL/f6kcz8Ncq7NPw6uus03Nhyd2oLnPCkQSrsFXKNAC18OUfix8lDia35iIoLoqh1t/ JQiFlo2Gw4YnT2v+AqHVv7w/+hdDHKX68rLMTNh95mc/ottWiYhO/BKQnzFBRUz3aJd0fiK6fsWFS QQ+9YZWw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1oKshy-00DVSQ-CB; Mon, 08 Aug 2022 02:41:34 +0000 From: "Matthew Wilcox (Oracle)" To: linux-kernel@vger.kernel.org, pmladek@suse.com, Kent Overstreet Cc: Johannes Weiner , Michal Hocko , Roman Gushchin Subject: [PATCH v5 22/32] mm/memcontrol.c: Convert to printbuf Date: Mon, 8 Aug 2022 03:41:18 +0100 Message-Id: <20220808024128.3219082-23-willy@infradead.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220808024128.3219082-1-willy@infradead.org> References: <20220808024128.3219082-1-willy@infradead.org> 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: Kent Overstreet This converts memory_stat_format() from seq_buf to printbuf. Printbuf is simalar to seq_buf except that it heap allocates the string buffer: here, we were already heap allocating the buffer with kmalloc() so the conversion is trivial. Signed-off-by: Kent Overstreet Cc: Johannes Weiner Cc: Michal Hocko Cc: Roman Gushchin Acked-by: Michal Hocko --- mm/memcontrol.c | 54 ++++++++++++++++++++++++------------------------- 1 file changed, 27 insertions(+), 27 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index b69979c9ced5..54897e4ac4ef 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -62,7 +62,7 @@ #include #include #include -#include +#include #include "internal.h" #include #include @@ -1490,13 +1490,10 @@ static const unsigned int memcg_vm_event_stat[] =3D= { #endif }; =20 -static void memory_stat_format(struct mem_cgroup *memcg, char *buf, int bu= fsize) +static void memory_stat_format(struct printbuf *out, struct mem_cgroup *me= mcg) { - struct seq_buf s; int i; =20 - seq_buf_init(&s, buf, bufsize); - /* * Provide statistics on the state of the memory subsystem as * well as cumulative event counters that show past behavior. @@ -1513,30 +1510,30 @@ static void memory_stat_format(struct mem_cgroup *m= emcg, char *buf, int bufsize) u64 size; =20 size =3D memcg_page_state_output(memcg, memory_stats[i].idx); - seq_buf_printf(&s, "%s %llu\n", memory_stats[i].name, size); + prt_printf(out, "%s %llu\n", memory_stats[i].name, size); =20 if (unlikely(memory_stats[i].idx =3D=3D NR_SLAB_UNRECLAIMABLE_B)) { size +=3D memcg_page_state_output(memcg, NR_SLAB_RECLAIMABLE_B); - seq_buf_printf(&s, "slab %llu\n", size); + prt_printf(out, "slab %llu\n", size); } } =20 /* Accumulated memory events */ - seq_buf_printf(&s, "pgscan %lu\n", - memcg_events(memcg, PGSCAN_KSWAPD) + - memcg_events(memcg, PGSCAN_DIRECT)); - seq_buf_printf(&s, "pgsteal %lu\n", - memcg_events(memcg, PGSTEAL_KSWAPD) + - memcg_events(memcg, PGSTEAL_DIRECT)); + prt_printf(out, "pgscan %lu\n", + memcg_events(memcg, PGSCAN_KSWAPD) + + memcg_events(memcg, PGSCAN_DIRECT)); + prt_printf(out, "pgsteal %lu\n", + memcg_events(memcg, PGSTEAL_KSWAPD) + + memcg_events(memcg, PGSTEAL_DIRECT)); =20 for (i =3D 0; i < ARRAY_SIZE(memcg_vm_event_stat); i++) - seq_buf_printf(&s, "%s %lu\n", - vm_event_name(memcg_vm_event_stat[i]), - memcg_events(memcg, memcg_vm_event_stat[i])); + prt_printf(out, "%s %lu\n", + vm_event_name(memcg_vm_event_stat[i]), + memcg_events(memcg, memcg_vm_event_stat[i])); =20 /* The above should easily fit into one page */ - WARN_ON_ONCE(seq_buf_has_overflowed(&s)); + WARN_ON_ONCE(!printbuf_remaining(out)); } =20 #define K(x) ((x) << (PAGE_SHIFT-10)) @@ -1573,7 +1570,8 @@ void mem_cgroup_print_oom_context(struct mem_cgroup *= memcg, struct task_struct * void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg) { /* Use static buffer, for the caller is holding oom_lock. */ - static char buf[PAGE_SIZE]; + static char _buf[PAGE_SIZE]; + struct printbuf buf =3D PRINTBUF_EXTERN(_buf, sizeof(_buf)); =20 lockdep_assert_held(&oom_lock); =20 @@ -1596,8 +1594,8 @@ void mem_cgroup_print_oom_meminfo(struct mem_cgroup *= memcg) pr_info("Memory cgroup stats for "); pr_cont_cgroup_path(memcg->css.cgroup); pr_cont(":"); - memory_stat_format(memcg, buf, sizeof(buf)); - pr_info("%s", buf); + memory_stat_format(&buf, memcg); + pr_info("%s", buf.buf); } =20 /* @@ -6401,14 +6399,16 @@ static int memory_events_local_show(struct seq_file= *m, void *v) static int memory_stat_show(struct seq_file *m, void *v) { struct mem_cgroup *memcg =3D mem_cgroup_from_seq(m); - char *buf =3D kmalloc(PAGE_SIZE, GFP_KERNEL); + struct printbuf buf =3D PRINTBUF; + int ret; =20 - if (!buf) - return -ENOMEM; - memory_stat_format(memcg, buf, PAGE_SIZE); - seq_puts(m, buf); - kfree(buf); - return 0; + memory_stat_format(&buf, memcg); + ret =3D buf.allocation_failure ? -ENOMEM : 0; + if (!ret) + seq_puts(m, buf.buf); + + printbuf_exit(&buf); + return ret; } =20 #ifdef CONFIG_NUMA --=20 2.35.1