From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: Petr Mladek <pmladek@suse.com>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Dmitriy Vyukov <dvyukov@google.com>,
Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Potapenko <glider@google.com>,
Fengguang Wu <fengguang.wu@intel.com>,
Josh Poimboeuf <jpoimboe@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Will Deacon <will.deacon@arm.com>,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Subject: [PATCH 2/3] mm: Use line-buffered printk() for show_free_areas().
Date: Fri, 2 Nov 2018 22:31:56 +0900 [thread overview]
Message-ID: <1541165517-3557-2-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <1541165517-3557-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp>
syzbot is sometimes getting mixed output like below due to concurrent
printk(). Mitigate such output by using line-buffered printk() API.
Node 0 DMA: 1*4kB (U) 0*8kB 0*16kB 1*32kB
syz-executor0: page allocation failure: order:0, mode:0x484020(GFP_ATOMIC|__GFP_COMP), nodemask=(null)
(U)
syz-executor0 cpuset=
2*64kB
syz0
(U)
mems_allowed=0
1*128kB
CPU: 0 PID: 7592 Comm: syz-executor0 Not tainted 4.19.0-rc6+ #118
(U)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
1*256kB (U)
Call Trace:
0*512kB
<IRQ>
1*1024kB
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113
(U)
1*2048kB
warn_alloc.cold.119+0xb7/0x1bd mm/page_alloc.c:3426
(M)
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
mm/page_alloc.c | 32 +++++++++++++++++---------------
1 file changed, 17 insertions(+), 15 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a919ba5..4411d5a 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4694,10 +4694,10 @@ unsigned long nr_free_pagecache_pages(void)
return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
}
-static inline void show_node(struct zone *zone)
+static inline void show_node(struct zone *zone, struct printk_buffer *buf)
{
if (IS_ENABLED(CONFIG_NUMA))
- printk("Node %d ", zone_to_nid(zone));
+ printk_buffered(buf, "Node %d ", zone_to_nid(zone));
}
long si_mem_available(void)
@@ -4814,7 +4814,7 @@ static bool show_mem_node_skip(unsigned int flags, int nid, nodemask_t *nodemask
#define K(x) ((x) << (PAGE_SHIFT-10))
-static void show_migration_types(unsigned char type)
+static void show_migration_types(unsigned char type, struct printk_buffer *buf)
{
static const char types[MIGRATE_TYPES] = {
[MIGRATE_UNMOVABLE] = 'U',
@@ -4838,7 +4838,7 @@ static void show_migration_types(unsigned char type)
}
*p = '\0';
- printk(KERN_CONT "(%s) ", tmp);
+ printk_buffered(buf, "(%s) ", tmp);
}
/*
@@ -4852,6 +4852,7 @@ static void show_migration_types(unsigned char type)
*/
void show_free_areas(unsigned int filter, nodemask_t *nodemask)
{
+ struct printk_buffer *buf = get_printk_buffer();
unsigned long free_pcp = 0;
int cpu;
struct zone *zone;
@@ -4950,8 +4951,8 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
for_each_online_cpu(cpu)
free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count;
- show_node(zone);
- printk(KERN_CONT
+ show_node(zone, buf);
+ printk_buffered(buf,
"%s"
" free:%lukB"
" min:%lukB"
@@ -4993,10 +4994,10 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
K(free_pcp),
K(this_cpu_read(zone->pageset->pcp.count)),
K(zone_page_state(zone, NR_FREE_CMA_PAGES)));
- printk("lowmem_reserve[]:");
+ printk_buffered(buf, "lowmem_reserve[]:");
for (i = 0; i < MAX_NR_ZONES; i++)
- printk(KERN_CONT " %ld", zone->lowmem_reserve[i]);
- printk(KERN_CONT "\n");
+ printk_buffered(buf, " %ld", zone->lowmem_reserve[i]);
+ printk_buffered(buf, "\n");
}
for_each_populated_zone(zone) {
@@ -5006,8 +5007,8 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
continue;
- show_node(zone);
- printk(KERN_CONT "%s: ", zone->name);
+ show_node(zone, buf);
+ printk_buffered(buf, "%s: ", zone->name);
spin_lock_irqsave(&zone->lock, flags);
for (order = 0; order < MAX_ORDER; order++) {
@@ -5025,12 +5026,12 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
}
spin_unlock_irqrestore(&zone->lock, flags);
for (order = 0; order < MAX_ORDER; order++) {
- printk(KERN_CONT "%lu*%lukB ",
- nr[order], K(1UL) << order);
+ printk_buffered(buf, "%lu*%lukB ",
+ nr[order], K(1UL) << order);
if (nr[order])
- show_migration_types(types[order]);
+ show_migration_types(types[order], buf);
}
- printk(KERN_CONT "= %lukB\n", K(total));
+ printk_buffered(buf, "= %lukB\n", K(total));
}
hugetlb_show_meminfo();
@@ -5038,6 +5039,7 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES));
show_swap_cache_info();
+ put_printk_buffer(buf);
}
static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
--
1.8.3.1
next prev parent reply other threads:[~2018-11-02 13:33 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-02 13:31 [PATCH v6 1/3] printk: Add line-buffered printk() API Tetsuo Handa
2018-11-02 13:31 ` Tetsuo Handa [this message]
2018-11-07 14:07 ` [PATCH 2/3] mm: Use line-buffered printk() for show_free_areas() Petr Mladek
2018-11-02 13:31 ` [PATCH 3/3] lockdep: Use line-buffered printk() for lockdep messages Tetsuo Handa
2018-11-02 13:36 ` Peter Zijlstra
2018-11-03 2:00 ` Tetsuo Handa
2018-11-06 8:38 ` Petr Mladek
2018-11-06 9:05 ` Sergey Senozhatsky
2018-11-06 12:57 ` Petr Mladek
2018-11-06 9:56 ` Tetsuo Handa
2018-11-07 15:19 ` Petr Mladek
2018-11-08 4:45 ` Sergey Senozhatsky
2018-11-08 11:37 ` Tetsuo Handa
2018-11-09 6:12 ` Sergey Senozhatsky
2018-11-09 9:55 ` Tetsuo Handa
2018-11-09 15:43 ` Petr Mladek
2018-11-10 2:42 ` Tetsuo Handa
2018-11-23 12:46 ` Petr Mladek
2018-11-23 13:12 ` Tetsuo Handa
2018-11-23 15:56 ` Steven Rostedt
2018-11-24 0:24 ` Tetsuo Handa
2018-11-26 4:34 ` Sergey Senozhatsky
2018-11-28 13:29 ` David Laight
2018-11-29 10:09 ` Tetsuo Handa
2018-11-30 16:01 ` Petr Mladek
2018-11-10 8:52 ` Tetsuo Handa
2018-11-23 12:52 ` Petr Mladek
2018-11-09 14:08 ` Linus Torvalds
2018-11-09 14:42 ` Steven Rostedt
2018-11-08 11:53 ` Petr Mladek
2018-11-08 12:44 ` Sergey Senozhatsky
2018-11-08 14:21 ` Sergey Senozhatsky
2018-11-09 9:54 ` Tetsuo Handa
2018-11-02 14:40 ` [PATCH v6 1/3] printk: Add line-buffered printk() API Matthew Wilcox
2018-11-03 1:55 ` Tetsuo Handa
2018-11-02 18:12 ` kbuild test robot
2018-11-06 14:35 ` Sergey Senozhatsky
2018-11-07 10:21 ` Petr Mladek
2018-11-07 12:54 ` Tetsuo Handa
2018-11-08 2:21 ` Sergey Senozhatsky
2018-11-08 11:24 ` Petr Mladek
2018-11-08 11:46 ` Tetsuo Handa
2018-11-08 12:30 ` Sergey Senozhatsky
2018-11-09 14:10 ` Petr Mladek
2018-11-12 7:59 ` Sergey Senozhatsky
2018-11-12 10:42 ` Tetsuo Handa
2018-11-17 10:14 ` Tetsuo Handa
2018-11-07 10:52 ` Tetsuo Handa
2018-11-07 11:01 ` David Laight
2018-11-07 12:00 ` Petr Mladek
2018-11-07 11:45 ` Petr Mladek
2018-11-08 2:30 ` Sergey Senozhatsky
2018-11-07 13:41 ` Petr Mladek
2018-11-07 14:06 ` Petr Mladek
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