The patch titled
Subject: mm/page_alloc.c: ratelimit allocation failure warnings more aggressively
has been added to the -mm tree. Its filename is
mm-rate-limit-allocation-failure-warnings-more-aggressively.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-rate-limit-allocation-failure-warnings-more-aggressively.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-rate-limit-allocation-failure-warnings-more-aggressively.patch
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------------------------------------------------------
From: Johannes Weiner <hannes@xxxxxxxxxxx>
Subject: mm/page_alloc.c: ratelimit allocation failure warnings more aggressively
While investigating a bug related to higher atomic allocation failures, we
noticed the failure warnings positively drowning the console, and in our
case trigger lockup warnings because of a serial console too slow to
handle all that output.
But even if we had a faster console, it's unclear what additional
information the current level of repetition provides.
Allocation failures happen for three reasons: The machine is OOM, the VM
is failing to handle reasonable requests, or somebody is making
unreasonable requests (and didn't acknowledge their opportunism with
__GFP_NOWARN). Having the memory dump, a callstack, and the ratelimit
stats on skipped failure warnings should provide enough information to let
users/admins/developers know whether something is wrong and point them in
the right direction for debugging, bpftracing etc.
Limit allocation failure warnings to 1 spew every ten seconds.
Link: http://lkml.kernel.org/r/20191028194906.26899-1-hannes@xxxxxxxxxxx
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
--- a/mm/page_alloc.c~mm-rate-limit-allocation-failure-warnings-more-aggressively
+++ a/mm/page_alloc.c
@@ -3728,10 +3728,6 @@ try_this_zone:
static void warn_alloc_show_mem(gfp_t gfp_mask, nodemask_t *nodemask)
{
unsigned int filter = SHOW_MEM_FILTER_NODES;
- static DEFINE_RATELIMIT_STATE(show_mem_rs, HZ, 1);
-
- if (!__ratelimit(&show_mem_rs))
- return;
/*
* This documents exceptions given to allocations in certain
@@ -3752,8 +3748,7 @@ void warn_alloc(gfp_t gfp_mask, nodemask
{
struct va_format vaf;
va_list args;
- static DEFINE_RATELIMIT_STATE(nopage_rs, DEFAULT_RATELIMIT_INTERVAL,
- DEFAULT_RATELIMIT_BURST);
+ static DEFINE_RATELIMIT_STATE(nopage_rs, 10*HZ, 1);
if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs))
return;
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
mm-rate-limit-allocation-failure-warnings-more-aggressively.patch
mm-memcontrol-remove-dead-code-from-memory_max_write.patch
mm-memcontrol-try-harder-to-set-a-new-memoryhigh.patch
mm-drop-mmap_sem-before-calling-balance_dirty_pages-in-write-fault.patch
