diff for duplicates of <20170518132033.GA12219@castle>
diff --git a/a/1.txt b/N1/1.txt
index d954fef..c3680f3 100644
--- a/a/1.txt
+++ b/N1/1.txt
@@ -20,109 +20,4 @@ Hi, Michal!
If we consider this approach, I've prepared a separate patch for this problem
(stripped all oom reaper list stuff).
-Thanks!
-
->From 317fad44a0fe79fb76e8e4fd6bd81c52ae1712e9 Mon Sep 17 00:00:00 2001
-From: Roman Gushchin <guro@fb.com>
-Date: Tue, 16 May 2017 21:19:56 +0100
-Subject: [PATCH] mm,oom: prevent OOM double kill from a pagefault handling
- path
-
-During the debugging of some OOM-related stuff, I've noticed
-that sometimes OOM kills two processes instead of one.
-
-The problem can be easily reproduced on a vanilla kernel:
-
-[ 25.721494] allocate invoked oom-killer: gfp_mask=0x14280ca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), nodemask=(null), order=0, oom_score_adj=0
-[ 25.725658] allocate cpuset=/ mems_allowed=0
-[ 25.727033] CPU: 1 PID: 492 Comm: allocate Not tainted 4.12.0-rc1-mm1+ #181
-[ 25.729215] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
-[ 25.729598] Call Trace:
-[ 25.729598] dump_stack+0x63/0x82
-[ 25.729598] dump_header+0x97/0x21a
-[ 25.729598] ? do_try_to_free_pages+0x2d7/0x360
-[ 25.729598] ? security_capable_noaudit+0x45/0x60
-[ 25.729598] oom_kill_process+0x219/0x3e0
-[ 25.729598] out_of_memory+0x11d/0x480
-[ 25.729598] __alloc_pages_slowpath+0xc84/0xd40
-[ 25.729598] __alloc_pages_nodemask+0x245/0x260
-[ 25.729598] alloc_pages_vma+0xa2/0x270
-[ 25.729598] __handle_mm_fault+0xca9/0x10c0
-[ 25.729598] handle_mm_fault+0xf3/0x210
-[ 25.729598] __do_page_fault+0x240/0x4e0
-[ 25.729598] trace_do_page_fault+0x37/0xe0
-[ 25.729598] do_async_page_fault+0x19/0x70
-[ 25.729598] async_page_fault+0x28/0x30
-< cut >
-[ 25.810868] oom_reaper: reaped process 492 (allocate), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
-< cut >
-[ 25.817589] allocate invoked oom-killer: gfp_mask=0x0(), nodemask=(null), order=0, oom_score_adj=0
-[ 25.818821] allocate cpuset=/ mems_allowed=0
-[ 25.819259] CPU: 1 PID: 492 Comm: allocate Not tainted 4.12.0-rc1-mm1+ #181
-[ 25.819847] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
-[ 25.820549] Call Trace:
-[ 25.820733] dump_stack+0x63/0x82
-[ 25.820961] dump_header+0x97/0x21a
-[ 25.820961] ? security_capable_noaudit+0x45/0x60
-[ 25.820961] oom_kill_process+0x219/0x3e0
-[ 25.820961] out_of_memory+0x11d/0x480
-[ 25.820961] pagefault_out_of_memory+0x68/0x80
-[ 25.820961] mm_fault_error+0x8f/0x190
-[ 25.820961] ? handle_mm_fault+0xf3/0x210
-[ 25.820961] __do_page_fault+0x4b2/0x4e0
-[ 25.820961] trace_do_page_fault+0x37/0xe0
-[ 25.820961] do_async_page_fault+0x19/0x70
-[ 25.820961] async_page_fault+0x28/0x30
-< cut >
-[ 25.863078] Out of memory: Kill process 233 (firewalld) score 10 or sacrifice child
-[ 25.863634] Killed process 233 (firewalld) total-vm:246076kB, anon-rss:20956kB, file-rss:0kB, shmem-rss:0kB
-
-This actually happens if pagefault_out_of_memory() is called
-after the calling process has already been selected as an OOM victim
-and killed. There is a race with the oom reaper: if the process
-is reaped before it enters out_of_memory(), the MMF_OOM_SKIP
-flag is set, and out_of_memory() will not consider the process
-as a eligible victim. That means that another victim will be selected
-and killed.
-
-Tetsuo Handa has noticed, that this is a side effect of
-commit 9a67f6488eca926f ("mm: consolidate GFP_NOFAIL checks
-in the allocator slowpath").
-
-To avoid this, out_of_memory() shouldn't be called from
-pagefault_out_of_memory(), if current task already
-has been chosen as an oom victim.
-
-v2: dropped changes related to the oom_reaper synchronization,
- as it looks like a separate and minor issue;
- rebased on new mm;
- renamed, updated commit message.
-
-Signed-off-by: Roman Gushchin <guro@fb.com>
-Cc: Michal Hocko <mhocko@suse.com>
-Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
-Cc: Johannes Weiner <hannes@cmpxchg.org>
-Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
-Cc: kernel-team@fb.com
-Cc: linux-mm@kvack.org
-Cc: linux-kernel@vger.kernel.org
----
- mm/oom_kill.c | 3 +++
- 1 file changed, 3 insertions(+)
-
-diff --git a/mm/oom_kill.c b/mm/oom_kill.c
-index 04c9143..9c643a3 100644
---- a/mm/oom_kill.c
-+++ b/mm/oom_kill.c
-@@ -1068,6 +1068,9 @@ void pagefault_out_of_memory(void)
- if (mem_cgroup_oom_synchronize(true))
- return;
-
-+ if (tsk_is_oom_victim(current))
-+ return;
-+
- if (!mutex_trylock(&oom_lock))
- return;
- out_of_memory(&oc);
---
-2.7.4
\ No newline at end of file
+Thanks!
\ No newline at end of file
diff --git a/a/content_digest b/N1/content_digest
index d015702..23c2c5f 100644
--- a/a/content_digest
+++ b/N1/content_digest
@@ -30,11 +30,11 @@
]
[
"Cc\0Tetsuo Handa <penguin-kernel\@i-love.sakura.ne.jp>",
- " <hannes\@cmpxchg.org>",
- " <vdavydov.dev\@gmail.com>",
- " <kernel-team\@fb.com>",
- " <linux-mm\@kvack.org>",
- " <linux-kernel\@vger.kernel.org>\0"
+ " hannes\@cmpxchg.org",
+ " vdavydov.dev\@gmail.com",
+ " kernel-team\@fb.com",
+ " linux-mm\@kvack.org",
+ " linux-kernel\@vger.kernel.org\0"
]
[
"\0000:1\0"
@@ -65,112 +65,7 @@
"If we consider this approach, I've prepared a separate patch for this problem\n",
"(stripped all oom reaper list stuff).\n",
"\n",
- "Thanks!\n",
- "\n",
- ">From 317fad44a0fe79fb76e8e4fd6bd81c52ae1712e9 Mon Sep 17 00:00:00 2001\n",
- "From: Roman Gushchin <guro\@fb.com>\n",
- "Date: Tue, 16 May 2017 21:19:56 +0100\n",
- "Subject: [PATCH] mm,oom: prevent OOM double kill from a pagefault handling\n",
- " path\n",
- "\n",
- "During the debugging of some OOM-related stuff, I've noticed\n",
- "that sometimes OOM kills two processes instead of one.\n",
- "\n",
- "The problem can be easily reproduced on a vanilla kernel:\n",
- "\n",
- "[ 25.721494] allocate invoked oom-killer: gfp_mask=0x14280ca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), nodemask=(null), order=0, oom_score_adj=0\n",
- "[ 25.725658] allocate cpuset=/ mems_allowed=0\n",
- "[ 25.727033] CPU: 1 PID: 492 Comm: allocate Not tainted 4.12.0-rc1-mm1+ #181\n",
- "[ 25.729215] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014\n",
- "[ 25.729598] Call Trace:\n",
- "[ 25.729598] dump_stack+0x63/0x82\n",
- "[ 25.729598] dump_header+0x97/0x21a\n",
- "[ 25.729598] ? do_try_to_free_pages+0x2d7/0x360\n",
- "[ 25.729598] ? security_capable_noaudit+0x45/0x60\n",
- "[ 25.729598] oom_kill_process+0x219/0x3e0\n",
- "[ 25.729598] out_of_memory+0x11d/0x480\n",
- "[ 25.729598] __alloc_pages_slowpath+0xc84/0xd40\n",
- "[ 25.729598] __alloc_pages_nodemask+0x245/0x260\n",
- "[ 25.729598] alloc_pages_vma+0xa2/0x270\n",
- "[ 25.729598] __handle_mm_fault+0xca9/0x10c0\n",
- "[ 25.729598] handle_mm_fault+0xf3/0x210\n",
- "[ 25.729598] __do_page_fault+0x240/0x4e0\n",
- "[ 25.729598] trace_do_page_fault+0x37/0xe0\n",
- "[ 25.729598] do_async_page_fault+0x19/0x70\n",
- "[ 25.729598] async_page_fault+0x28/0x30\n",
- "< cut >\n",
- "[ 25.810868] oom_reaper: reaped process 492 (allocate), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB\n",
- "< cut >\n",
- "[ 25.817589] allocate invoked oom-killer: gfp_mask=0x0(), nodemask=(null), order=0, oom_score_adj=0\n",
- "[ 25.818821] allocate cpuset=/ mems_allowed=0\n",
- "[ 25.819259] CPU: 1 PID: 492 Comm: allocate Not tainted 4.12.0-rc1-mm1+ #181\n",
- "[ 25.819847] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014\n",
- "[ 25.820549] Call Trace:\n",
- "[ 25.820733] dump_stack+0x63/0x82\n",
- "[ 25.820961] dump_header+0x97/0x21a\n",
- "[ 25.820961] ? security_capable_noaudit+0x45/0x60\n",
- "[ 25.820961] oom_kill_process+0x219/0x3e0\n",
- "[ 25.820961] out_of_memory+0x11d/0x480\n",
- "[ 25.820961] pagefault_out_of_memory+0x68/0x80\n",
- "[ 25.820961] mm_fault_error+0x8f/0x190\n",
- "[ 25.820961] ? handle_mm_fault+0xf3/0x210\n",
- "[ 25.820961] __do_page_fault+0x4b2/0x4e0\n",
- "[ 25.820961] trace_do_page_fault+0x37/0xe0\n",
- "[ 25.820961] do_async_page_fault+0x19/0x70\n",
- "[ 25.820961] async_page_fault+0x28/0x30\n",
- "< cut >\n",
- "[ 25.863078] Out of memory: Kill process 233 (firewalld) score 10 or sacrifice child\n",
- "[ 25.863634] Killed process 233 (firewalld) total-vm:246076kB, anon-rss:20956kB, file-rss:0kB, shmem-rss:0kB\n",
- "\n",
- "This actually happens if pagefault_out_of_memory() is called\n",
- "after the calling process has already been selected as an OOM victim\n",
- "and killed. There is a race with the oom reaper: if the process\n",
- "is reaped before it enters out_of_memory(), the MMF_OOM_SKIP\n",
- "flag is set, and out_of_memory() will not consider the process\n",
- "as a eligible victim. That means that another victim will be selected\n",
- "and killed.\n",
- "\n",
- "Tetsuo Handa has noticed, that this is a side effect of\n",
- "commit 9a67f6488eca926f (\"mm: consolidate GFP_NOFAIL checks\n",
- "in the allocator slowpath\").\n",
- "\n",
- "To avoid this, out_of_memory() shouldn't be called from\n",
- "pagefault_out_of_memory(), if current task already\n",
- "has been chosen as an oom victim.\n",
- "\n",
- "v2: dropped changes related to the oom_reaper synchronization,\n",
- " as it looks like a separate and minor issue;\n",
- " rebased on new mm;\n",
- " renamed, updated commit message.\n",
- "\n",
- "Signed-off-by: Roman Gushchin <guro\@fb.com>\n",
- "Cc: Michal Hocko <mhocko\@suse.com>\n",
- "Cc: Tetsuo Handa <penguin-kernel\@I-love.SAKURA.ne.jp>\n",
- "Cc: Johannes Weiner <hannes\@cmpxchg.org>\n",
- "Cc: Vladimir Davydov <vdavydov.dev\@gmail.com>\n",
- "Cc: kernel-team\@fb.com\n",
- "Cc: linux-mm\@kvack.org\n",
- "Cc: linux-kernel\@vger.kernel.org\n",
- "---\n",
- " mm/oom_kill.c | 3 +++\n",
- " 1 file changed, 3 insertions(+)\n",
- "\n",
- "diff --git a/mm/oom_kill.c b/mm/oom_kill.c\n",
- "index 04c9143..9c643a3 100644\n",
- "--- a/mm/oom_kill.c\n",
- "+++ b/mm/oom_kill.c\n",
- "\@\@ -1068,6 +1068,9 \@\@ void pagefault_out_of_memory(void)\n",
- " \tif (mem_cgroup_oom_synchronize(true))\n",
- " \t\treturn;\n",
- " \n",
- "+\tif (tsk_is_oom_victim(current))\n",
- "+\t\treturn;\n",
- "+\n",
- " \tif (!mutex_trylock(&oom_lock))\n",
- " \t\treturn;\n",
- " \tout_of_memory(&oc);\n",
- "-- \n",
- "2.7.4"
+ "Thanks!"
]
-71286ffb0939b64b3a19ec7c4fa5ec7108656a3fd206318125f60241a45dc0e4
+369b4f9788e1003f0ab13a9e782b456b7cd36c189fb9e12e7ff06583bebc7595
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