@@ -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)
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(-)