From: Michal Hocko <mhocko@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
linux-mm@kvack.org, "David (ChunMing) Zhou" <David1.Zhou@amd.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Alex Deucher" <alexander.deucher@amd.com>,
"David Airlie" <airlied@linux.ie>,
"Jani Nikula" <jani.nikula@linux.intel.com>,
"Joonas Lahtinen" <joonas.lahtinen@linux.intel.com>,
"Rodrigo Vivi" <rodrigo.vivi@intel.com>,
"Doug Ledford" <dledford@redhat.com>,
"Jason Gunthorpe" <jgg@ziepe.ca>,
"Mike Marciniszyn" <mike.marciniszyn@intel.com>,
"Dennis Dalessandro" <dennis.dalessandro@intel.com>,
"Sudeep Dutt" <sudeep.dutt@intel.com>,
"Ashutosh Dixit" <ashutosh.dixit@intel.com>,
"Dimitri Sivanich" <sivanich@sgi.com>,
"Boris Ostrovsky" <boris.ostrovsky@oracle.com>,
"Juergen Gross" <jgross@suse.com>,
"Jérôme Glisse" <jglisse@redhat.com>,
"Andrea Arcangeli" <aarcange@redhat.com>,
"Felix Kuehling" <felix.kuehling@amd.com>,
kvm@vger.kernel.org, amd-gfx@lists.freedesktop.org,
dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org,
linux-rdma@vger.kernel.org, xen-devel@lists.xenproject.org,
"Christian König" <christian.koenig@amd.com>,
"David Rientjes" <rientjes@google.com>,
"Leon Romanovsky" <leonro@mellanox.com>
Subject: Re: [PATCH] mm, oom: distinguish blockable mode for mmu notifiers
Date: Tue, 24 Jul 2018 16:17:47 +0200 [thread overview]
Message-ID: <20180724141747.GP28386@dhcp22.suse.cz> (raw)
In-Reply-To: <20180720170902.d1137060c23802d55426aa03@linux-foundation.org>
On Fri 20-07-18 17:09:02, Andrew Morton wrote:
[...]
> - Undocumented return value.
>
> - comment "failed to reap part..." is misleading - sounds like it's
> referring to something which happened in the past, is in fact
> referring to something which might happen in the future.
>
> - fails to call trace_finish_task_reaping() in one case
>
> - code duplication.
>
> - Increases mmap_sem hold time a little by moving
> trace_finish_task_reaping() inside the locked region. So sue me ;)
>
> - Sharing the finish: path means that the trace event won't
> distinguish between the two sources of finishing.
>
> Please take a look?
oom_reap_task_mm should return false when __oom_reap_task_mm return
false. This is what my patch did but it seems this changed by
http://www.ozlabs.org/~akpm/mmotm/broken-out/mm-oom-remove-oom_lock-from-oom_reaper.patch
so that one should be fixed.
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 104ef4a01a55..88657e018714 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -565,7 +565,7 @@ static bool oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
/* failed to reap part of the address space. Try again later */
if (!__oom_reap_task_mm(mm)) {
up_read(&mm->mmap_sem);
- return true;
+ return false;
}
pr_info("oom_reaper: reaped process %d (%s), now anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n",
On top of that the proposed cleanup looks as follows:
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 88657e018714..4e185a282b3d 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -541,8 +541,16 @@ bool __oom_reap_task_mm(struct mm_struct *mm)
return ret;
}
+/*
+ * Reaps the address space of the give task.
+ *
+ * Returns true on success and false if none or part of the address space
+ * has been reclaimed and the caller should retry later.
+ */
static bool oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
{
+ bool ret = true;
+
if (!down_read_trylock(&mm->mmap_sem)) {
trace_skip_task_reaping(tsk->pid);
return false;
@@ -555,28 +563,28 @@ static bool oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
* down_write();up_write() cycle in exit_mmap().
*/
if (test_bit(MMF_OOM_SKIP, &mm->flags)) {
- up_read(&mm->mmap_sem);
trace_skip_task_reaping(tsk->pid);
- return true;
+ goto out_unlock;
}
trace_start_task_reaping(tsk->pid);
/* failed to reap part of the address space. Try again later */
- if (!__oom_reap_task_mm(mm)) {
- up_read(&mm->mmap_sem);
- return false;
- }
+ ret = __oom_reap_task_mm(mm);
+ if (!ret)
+ goto out_finish;
pr_info("oom_reaper: reaped process %d (%s), now anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n",
task_pid_nr(tsk), tsk->comm,
K(get_mm_counter(mm, MM_ANONPAGES)),
K(get_mm_counter(mm, MM_FILEPAGES)),
K(get_mm_counter(mm, MM_SHMEMPAGES)));
+out_finish:
+ trace_finish_task_reaping(tsk->pid);
+out_unlock:
up_read(&mm->mmap_sem);
- trace_finish_task_reaping(tsk->pid);
- return true;
+ return ret;
}
#define MAX_OOM_REAP_RETRIES 10
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2018-07-24 14:18 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-16 11:50 [PATCH] mm, oom: distinguish blockable mode for mmu notifiers Michal Hocko
2018-07-16 23:12 ` Andrew Morton
2018-07-17 4:03 ` Leon Romanovsky
2018-07-17 8:12 ` Michal Hocko
2018-07-20 23:01 ` Andrew Morton
2018-07-23 8:43 ` Michal Hocko
2018-07-19 9:12 ` Michal Hocko
2018-07-21 0:09 ` Andrew Morton
2018-07-23 7:03 ` Michal Hocko
2018-07-23 7:11 ` Michal Hocko
2018-07-23 8:11 ` Michal Hocko
2018-07-24 14:17 ` Michal Hocko [this message]
2018-07-24 19:53 ` Andrew Morton
2018-07-25 6:17 ` Michal Hocko
2018-07-24 21:07 ` David Rientjes
2018-07-25 6:13 ` Michal Hocko
2018-08-24 10:54 ` Tetsuo Handa
2018-08-24 11:32 ` Michal Hocko
2018-08-24 11:43 ` Christian König
2018-08-24 11:52 ` Michal Hocko
2018-08-24 11:57 ` Christian König
2018-08-24 12:03 ` Michal Hocko
2018-08-24 12:18 ` Christian König
2018-08-24 12:33 ` Michal Hocko
2018-08-24 12:52 ` Christian König
2018-08-24 13:01 ` Michal Hocko
2018-08-24 13:10 ` Christian König
2018-08-24 13:24 ` Michal Hocko
2018-08-24 13:28 ` Christian König
2018-08-24 13:40 ` Michal Hocko
2018-08-24 13:44 ` Christian König
2018-08-24 13:52 ` Michal Hocko
2018-08-26 8:40 ` Tetsuo Handa
2018-08-27 7:41 ` Christian König
2018-09-06 22:46 ` Tetsuo Handa
2018-08-24 15:08 ` Jerome Glisse
2018-08-24 11:36 ` Michal Hocko
2018-08-24 13:02 ` Tetsuo Handa
2018-08-24 13:32 ` Michal Hocko
2018-08-24 14:52 ` Tetsuo Handa
2018-08-24 15:12 ` Jerome Glisse
2018-08-24 16:40 ` Michal Hocko
2018-08-24 17:33 ` Jerome Glisse
2018-08-24 16:38 ` Michal Hocko
2018-08-24 14:40 ` Jerome Glisse
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