From patchwork Wed Nov 22 23:25:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kent Overstreet X-Patchwork-Id: 13465561 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D64D2C61D97 for ; Wed, 22 Nov 2023 23:25:35 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A5B186B05EF; Wed, 22 Nov 2023 18:25:32 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 921256B05F0; Wed, 22 Nov 2023 18:25:32 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 775FE6B05F1; Wed, 22 Nov 2023 18:25:32 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 607026B05EF for ; Wed, 22 Nov 2023 18:25:32 -0500 (EST) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 39189A0F08 for ; Wed, 22 Nov 2023 23:25:32 +0000 (UTC) X-FDA: 81487174104.22.3F3C234 Received: from out-181.mta0.migadu.com (out-181.mta0.migadu.com [91.218.175.181]) by imf08.hostedemail.com (Postfix) with ESMTP id 7B4AF16000D for ; Wed, 22 Nov 2023 23:25:30 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=KVh3wxKI; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf08.hostedemail.com: domain of kent.overstreet@linux.dev designates 91.218.175.181 as permitted sender) smtp.mailfrom=kent.overstreet@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1700695530; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=RfcqUFguaDDZw+gf+d0LSy3BejslhVkAhwRYXLWAYww=; b=F6usg9crMoms9NCeB4jh97iOG1LS6bbBXJWTkvnn1J5DamChIyvNJptD1RCb2/cpBjMkpT koamTDfdJX65RdHo3l68xcm8l2XIQpW+vSph1+huEKBT4fglr/e4gpPxXFlTsk5SW8ZlCJ oIN0nbXxFua2JgV27ReRYk/sP3C5WzI= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=KVh3wxKI; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf08.hostedemail.com: domain of kent.overstreet@linux.dev designates 91.218.175.181 as permitted sender) smtp.mailfrom=kent.overstreet@linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1700695530; a=rsa-sha256; cv=none; b=1s1ljvtmlMetb9BehLskd3YYFGSNEKgL59LZmYk+fe8yKYfDQ/MWfiBDHZvRWkuy5S+X0C seVnntWWzorA6mmjc5syBP3/m9zy+Bl4T+ruvOMDfuoDC6X7peWkRCMIXnz3zujwHBMUAo gAg2voRdoRpdPhUG1mx4mpvXr7ButD4= 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=1700695529; 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=RfcqUFguaDDZw+gf+d0LSy3BejslhVkAhwRYXLWAYww=; b=KVh3wxKIo4UY3M0nKsfWud9MNgWoL2E3pERfHvOTCAkXnvsURoSqAEjUmPalhXUSNLrOps qL0Vq27zCcEV27nYL27phxtsnLF4sUXNJKSd1c90XA5LM5BNTphc9LQscyej8ZjxlFAQtj zdogso5LeCN9DCAJz2BtPcz5+k96adw= From: Kent Overstreet To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Kent Overstreet , Andrew Morton , Qi Zheng , Roman Gushchin Subject: [PATCH 4/7] mm: Centralize & improve oom reporting in show_mem.c Date: Wed, 22 Nov 2023 18:25:09 -0500 Message-ID: <20231122232515.177833-5-kent.overstreet@linux.dev> In-Reply-To: <20231122232515.177833-1-kent.overstreet@linux.dev> References: <20231122232515.177833-1-kent.overstreet@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 7B4AF16000D X-Stat-Signature: 58kfu7fuhpxpp9aqga8ge53timywyb3f X-HE-Tag: 1700695530-288587 X-HE-Meta: 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 0nDQQD7o ZSPD+dG7t8y3ncTA3xP3Ge8RxgED6qaHbqJXCtHhoNOaxpdZQ5+3M1A4q9jn5AMhdvqh6f5zEuaN7YuBwmrXNbYgCl2qy5N5AdXaXBcCHp7HUWG8+qxVdeiiQh3NuzskjnHGEwUqQCTBIGzwYKOj01zv40EL3jirJ5W84KVJ9ZeHNpDPbyItxAdPqgZtLdEVrLElQ0/vm6fD5/1BMmttQrTRzNmBmWKnItH2vIuRdNIPgcg6zI5/QNd9f1MgZdb0yviD62ZHwQraCiQh2E+WMVddAN1otlYCu0z6VOhrEMIqUcUJdjgxh6WinTg== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: This patch: - Changes show_mem() to always report on slab usage - Instead of reporting on all slabs, we only report on top 10 slabs, and in sorted order - Also reports on shrinkers, with the new shrinkers_to_text(). Shrinkers need to be included in OOM/allocation failure reporting because they're responsible for memory reclaim - if a shrinker isn't giving up its memory, we need to know which one and why. More OOM reporting can be moved to show_mem.c and improved, this patch is only a start. New example output on OOM/memory allocation failure: 00177 Mem-Info: 00177 active_anon:13706 inactive_anon:32266 isolated_anon:16 00177 active_file:1653 inactive_file:1822 isolated_file:0 00177 unevictable:0 dirty:0 writeback:0 00177 slab_reclaimable:6242 slab_unreclaimable:11168 00177 mapped:3824 shmem:3 pagetables:1266 bounce:0 00177 kernel_misc_reclaimable:0 00177 free:4362 free_pcp:35 free_cma:0 00177 Node 0 active_anon:54824kB inactive_anon:129064kB active_file:6612kB inactive_file:7288kB unevictable:0kB isolated(anon):64kB isolated(file):0kB mapped:15296kB dirty:0kB writeback:0kB shmem:12kB writeback_tmp:0kB kernel_stack:3392kB pagetables:5064kB all_unreclaimable? no 00177 DMA free:2232kB boost:0kB min:88kB low:108kB high:128kB reserved_highatomic:0KB active_anon:2924kB inactive_anon:6596kB active_file:428kB inactive_file:384kB unevictable:0kB writepending:0kB present:15992kB managed:15360kB mlocked:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB 00177 lowmem_reserve[]: 0 426 426 426 00177 DMA32 free:15092kB boost:5836kB min:8432kB low:9080kB high:9728kB reserved_highatomic:0KB active_anon:52196kB inactive_anon:122392kB active_file:6176kB inactive_file:7068kB unevictable:0kB writepending:0kB present:507760kB managed:441816kB mlocked:0kB bounce:0kB free_pcp:72kB local_pcp:0kB free_cma:0kB 00177 lowmem_reserve[]: 0 0 0 0 00177 DMA: 284*4kB (UM) 53*8kB (UM) 21*16kB (U) 11*32kB (U) 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 2248kB 00177 DMA32: 2765*4kB (UME) 375*8kB (UME) 57*16kB (UM) 5*32kB (U) 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 15132kB 00177 4656 total pagecache pages 00177 1031 pages in swap cache 00177 Swap cache stats: add 6572399, delete 6572173, find 488603/3286476 00177 Free swap = 509112kB 00177 Total swap = 2097148kB 00177 130938 pages RAM 00177 0 pages HighMem/MovableOnly 00177 16644 pages reserved 00177 Unreclaimable slab info: 00177 9p-fcall-cache total: 8.25 MiB active: 8.25 MiB 00177 kernfs_node_cache total: 2.15 MiB active: 2.15 MiB 00177 kmalloc-64 total: 2.08 MiB active: 2.07 MiB 00177 task_struct total: 1.95 MiB active: 1.95 MiB 00177 kmalloc-4k total: 1.50 MiB active: 1.50 MiB 00177 signal_cache total: 1.34 MiB active: 1.34 MiB 00177 kmalloc-2k total: 1.16 MiB active: 1.16 MiB 00177 bch_inode_info total: 1.02 MiB active: 922 KiB 00177 perf_event total: 1.02 MiB active: 1.02 MiB 00177 biovec-max total: 992 KiB active: 960 KiB 00177 Shrinkers: 00177 super_cache_scan: objects: 127 00177 super_cache_scan: objects: 106 00177 jbd2_journal_shrink_scan: objects: 32 00177 ext4_es_scan: objects: 32 00177 bch2_btree_cache_scan: objects: 8 00177 nr nodes: 24 00177 nr dirty: 0 00177 cannibalize lock: 0000000000000000 00177 00177 super_cache_scan: objects: 8 00177 super_cache_scan: objects: 1 Cc: Andrew Morton Cc: Qi Zheng Cc: Roman Gushchin Cc: linux-mm@kvack.org Signed-off-by: Kent Overstreet --- mm/oom_kill.c | 23 --------------------- mm/show_mem.c | 20 +++++++++++++++++++ mm/slab.h | 6 ++++-- mm/slab_common.c | 52 +++++++++++++++++++++++++++++++++++++++--------- 4 files changed, 67 insertions(+), 34 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 9e6071fde34a..4b825a2b353f 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -168,27 +168,6 @@ static bool oom_unkillable_task(struct task_struct *p) return false; } -/* - * Check whether unreclaimable slab amount is greater than - * all user memory(LRU pages). - * dump_unreclaimable_slab() could help in the case that - * oom due to too much unreclaimable slab used by kernel. -*/ -static bool should_dump_unreclaim_slab(void) -{ - unsigned long nr_lru; - - nr_lru = global_node_page_state(NR_ACTIVE_ANON) + - global_node_page_state(NR_INACTIVE_ANON) + - global_node_page_state(NR_ACTIVE_FILE) + - global_node_page_state(NR_INACTIVE_FILE) + - global_node_page_state(NR_ISOLATED_ANON) + - global_node_page_state(NR_ISOLATED_FILE) + - global_node_page_state(NR_UNEVICTABLE); - - return (global_node_page_state_pages(NR_SLAB_UNRECLAIMABLE_B) > nr_lru); -} - /** * oom_badness - heuristic function to determine which candidate task to kill * @p: task struct of which task we should calculate @@ -462,8 +441,6 @@ static void dump_header(struct oom_control *oc) mem_cgroup_print_oom_meminfo(oc->memcg); else { __show_mem(SHOW_MEM_FILTER_NODES, oc->nodemask, gfp_zone(oc->gfp_mask)); - if (should_dump_unreclaim_slab()) - dump_unreclaimable_slab(); } if (sysctl_oom_dump_tasks) dump_tasks(oc); diff --git a/mm/show_mem.c b/mm/show_mem.c index ba0808d6917f..ab258ab1161c 100644 --- a/mm/show_mem.c +++ b/mm/show_mem.c @@ -12,10 +12,12 @@ #include #include #include +#include #include #include #include "internal.h" +#include "slab.h" #include "swap.h" atomic_long_t _totalram_pages __read_mostly; @@ -401,6 +403,7 @@ void __show_mem(unsigned int filter, nodemask_t *nodemask, int max_zone_idx) { unsigned long total = 0, reserved = 0, highmem = 0; struct zone *zone; + char *buf; printk("Mem-Info:\n"); show_free_areas(filter, nodemask, max_zone_idx); @@ -423,4 +426,21 @@ void __show_mem(unsigned int filter, nodemask_t *nodemask, int max_zone_idx) #ifdef CONFIG_MEMORY_FAILURE printk("%lu pages hwpoisoned\n", atomic_long_read(&num_poisoned_pages)); #endif + + buf = kmalloc(4096, GFP_ATOMIC); + if (buf) { + struct seq_buf s; + + printk("Unreclaimable slab info:\n"); + seq_buf_init(&s, buf, 4096); + dump_unreclaimable_slab(&s); + printk("%s", seq_buf_str(&s)); + + printk("Shrinkers:\n"); + seq_buf_init(&s, buf, 4096); + shrinkers_to_text(&s); + printk("%s", seq_buf_str(&s)); + + kfree(buf); + } } diff --git a/mm/slab.h b/mm/slab.h index 3d07fb428393..c16358a8424c 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -818,10 +818,12 @@ static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) if ((__n = get_node(__s, __node))) +struct seq_buf; + #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) -void dump_unreclaimable_slab(void); +void dump_unreclaimable_slab(struct seq_buf *); #else -static inline void dump_unreclaimable_slab(void) +static inline void dump_unreclaimable_slab(struct seq_buf *out) { } #endif diff --git a/mm/slab_common.c b/mm/slab_common.c index 8d431193c273..1eadff512422 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include "internal.h" @@ -1295,10 +1296,15 @@ static int slab_show(struct seq_file *m, void *p) return 0; } -void dump_unreclaimable_slab(void) +void dump_unreclaimable_slab(struct seq_buf *out) { struct kmem_cache *s; struct slabinfo sinfo; + struct slab_by_mem { + struct kmem_cache *s; + size_t total, active; + } slabs_by_mem[10], n; + int i, nr = 0; /* * Here acquiring slab_mutex is risky since we don't prefer to get @@ -1308,24 +1314,52 @@ void dump_unreclaimable_slab(void) * without acquiring the mutex. */ if (!mutex_trylock(&slab_mutex)) { - pr_warn("excessive unreclaimable slab but cannot dump stats\n"); + seq_buf_puts(out, "excessive unreclaimable slab but cannot dump stats\n"); return; } - pr_info("Unreclaimable slab info:\n"); - pr_info("Name Used Total\n"); - list_for_each_entry(s, &slab_caches, list) { if (s->flags & SLAB_RECLAIM_ACCOUNT) continue; get_slabinfo(s, &sinfo); - if (sinfo.num_objs > 0) - pr_info("%-17s %10luKB %10luKB\n", s->name, - (sinfo.active_objs * s->size) / 1024, - (sinfo.num_objs * s->size) / 1024); + if (!sinfo.num_objs) + continue; + + n.s = s; + n.total = sinfo.num_objs * s->size; + n.active = sinfo.active_objs * s->size; + + for (i = 0; i < nr; i++) + if (n.total < slabs_by_mem[i].total) + break; + + if (nr < ARRAY_SIZE(slabs_by_mem)) { + memmove(&slabs_by_mem[i + 1], + &slabs_by_mem[i], + sizeof(slabs_by_mem[0]) * (nr - i)); + nr++; + } else if (i) { + i--; + memmove(&slabs_by_mem[0], + &slabs_by_mem[1], + sizeof(slabs_by_mem[0]) * i); + } else { + continue; + } + + slabs_by_mem[i] = n; + } + + for (i = nr - 1; i >= 0; --i) { + seq_buf_printf(out, "%-17s total: ", slabs_by_mem[i].s->name); + seq_buf_human_readable_u64(out, slabs_by_mem[i].total, STRING_UNITS_2); + seq_buf_printf(out, " active: "); + seq_buf_human_readable_u64(out, slabs_by_mem[i].active, STRING_UNITS_2); + seq_buf_putc(out, '\n'); } + mutex_unlock(&slab_mutex); }