From: "Christian König" <christian.koenig@amd.com>
To: Michal Hocko <mhocko@suse.com>
Cc: "Christian König" <ckoenig.leichtzumerken@gmail.com>,
linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
intel-gfx@lists.freedesktop.org, amd-gfx@lists.freedesktop.org,
nouveau@lists.freedesktop.org, linux-tegra@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
alexander.deucher@amd.com, daniel@ffwll.ch,
viro@zeniv.linux.org.uk, akpm@linux-foundation.org,
hughd@google.com, andrey.grodzovsky@amd.com
Subject: Re: [PATCH 03/13] mm: shmem: provide oom badness for shmem files
Date: Wed, 15 Jun 2022 16:24:10 +0200 [thread overview]
Message-ID: <3ef8af8b-2dfa-79cf-e7cd-8a3e5ec20d6c@amd.com> (raw)
In-Reply-To: <Yqnba1E2FSRVUATY@dhcp22.suse.cz>
Am 15.06.22 um 15:15 schrieb Michal Hocko:
> On Wed 15-06-22 14:35:22, Christian König wrote:
> [...]
>> Even the classic mm_struct based accounting includes MM_SHMEMPAGES into the
>> badness. So accounting shared resources as badness to make a decision is
>> nothing new here.
> Yeah, it is nothing really new but it also doesn't mean it is an example
> worth following as this doesn't really work currently. Also please note
> that MM_SHMEMPAGES is counting at least something process specific as
> those pages are mapped in to the process (and with enough of wishful
> thinking unmapping can drop the last reference and free something up
> actually) . With generic per-file memory this is even more detached from
> process.
But this is exactly the use case here. See I do have the 1% which is
shared between processes, but 99% of the allocations only one process
has a reference to them.
So that wishful thinking that we can drop the last reference when we
kill this specific process is perfectly justified.
It can be that this doesn't fit all use cases for the shmem file, but it
certainly does for DRM and DMA-buf.
>> The difference is that this time the badness doesn't come from the memory
>> management subsystem, but rather from the I/O subsystem.
>>
>>> This is also the reason why I am not really fan of the per file
>>> badness because it adds a notion of resource that is not process bound
>>> in general so it will add all sorts of weird runtime corner cases which
>>> are impossible to anticipate [*]. Maybe that will work in some scenarios
>>> but definitely not something to be done by default without users opting
>>> into that and being aware of consequences.
>> Would a kernel command line option to control the behavior be helpful here?
> I am not sure what would be the proper way to control that that would be
> future extensible. Kernel command line is certainly and option but if we
> want to extend that to module like or eBPF interface then it wouldn't
> stand a future test very quickly.
Well kernel command lines are not really meant to be stable, aren't they?
Regards,
Christian.
WARNING: multiple messages have this Message-ID (diff)
From: "Christian König" <christian.koenig@amd.com>
To: Michal Hocko <mhocko@suse.com>
Cc: andrey.grodzovsky@amd.com, linux-mm@kvack.org,
nouveau@lists.freedesktop.org, intel-gfx@lists.freedesktop.org,
hughd@google.com, linux-kernel@vger.kernel.org,
amd-gfx@lists.freedesktop.org, linux-fsdevel@vger.kernel.org,
viro@zeniv.linux.org.uk, daniel@ffwll.ch,
"Christian König" <ckoenig.leichtzumerken@gmail.com>,
linux-tegra@vger.kernel.org, alexander.deucher@amd.com,
akpm@linux-foundation.org, linux-media@vger.kernel.org
Subject: Re: [Nouveau] [PATCH 03/13] mm: shmem: provide oom badness for shmem files
Date: Wed, 15 Jun 2022 16:24:10 +0200 [thread overview]
Message-ID: <3ef8af8b-2dfa-79cf-e7cd-8a3e5ec20d6c@amd.com> (raw)
In-Reply-To: <Yqnba1E2FSRVUATY@dhcp22.suse.cz>
Am 15.06.22 um 15:15 schrieb Michal Hocko:
> On Wed 15-06-22 14:35:22, Christian König wrote:
> [...]
>> Even the classic mm_struct based accounting includes MM_SHMEMPAGES into the
>> badness. So accounting shared resources as badness to make a decision is
>> nothing new here.
> Yeah, it is nothing really new but it also doesn't mean it is an example
> worth following as this doesn't really work currently. Also please note
> that MM_SHMEMPAGES is counting at least something process specific as
> those pages are mapped in to the process (and with enough of wishful
> thinking unmapping can drop the last reference and free something up
> actually) . With generic per-file memory this is even more detached from
> process.
But this is exactly the use case here. See I do have the 1% which is
shared between processes, but 99% of the allocations only one process
has a reference to them.
So that wishful thinking that we can drop the last reference when we
kill this specific process is perfectly justified.
It can be that this doesn't fit all use cases for the shmem file, but it
certainly does for DRM and DMA-buf.
>> The difference is that this time the badness doesn't come from the memory
>> management subsystem, but rather from the I/O subsystem.
>>
>>> This is also the reason why I am not really fan of the per file
>>> badness because it adds a notion of resource that is not process bound
>>> in general so it will add all sorts of weird runtime corner cases which
>>> are impossible to anticipate [*]. Maybe that will work in some scenarios
>>> but definitely not something to be done by default without users opting
>>> into that and being aware of consequences.
>> Would a kernel command line option to control the behavior be helpful here?
> I am not sure what would be the proper way to control that that would be
> future extensible. Kernel command line is certainly and option but if we
> want to extend that to module like or eBPF interface then it wouldn't
> stand a future test very quickly.
Well kernel command lines are not really meant to be stable, aren't they?
Regards,
Christian.
WARNING: multiple messages have this Message-ID (diff)
From: "Christian König" <christian.koenig@amd.com>
To: Michal Hocko <mhocko@suse.com>
Cc: andrey.grodzovsky@amd.com, linux-mm@kvack.org,
nouveau@lists.freedesktop.org, intel-gfx@lists.freedesktop.org,
hughd@google.com, linux-kernel@vger.kernel.org,
amd-gfx@lists.freedesktop.org, linux-fsdevel@vger.kernel.org,
viro@zeniv.linux.org.uk,
"Christian König" <ckoenig.leichtzumerken@gmail.com>,
linux-tegra@vger.kernel.org, alexander.deucher@amd.com,
akpm@linux-foundation.org, linux-media@vger.kernel.org
Subject: Re: [Intel-gfx] [PATCH 03/13] mm: shmem: provide oom badness for shmem files
Date: Wed, 15 Jun 2022 16:24:10 +0200 [thread overview]
Message-ID: <3ef8af8b-2dfa-79cf-e7cd-8a3e5ec20d6c@amd.com> (raw)
In-Reply-To: <Yqnba1E2FSRVUATY@dhcp22.suse.cz>
Am 15.06.22 um 15:15 schrieb Michal Hocko:
> On Wed 15-06-22 14:35:22, Christian König wrote:
> [...]
>> Even the classic mm_struct based accounting includes MM_SHMEMPAGES into the
>> badness. So accounting shared resources as badness to make a decision is
>> nothing new here.
> Yeah, it is nothing really new but it also doesn't mean it is an example
> worth following as this doesn't really work currently. Also please note
> that MM_SHMEMPAGES is counting at least something process specific as
> those pages are mapped in to the process (and with enough of wishful
> thinking unmapping can drop the last reference and free something up
> actually) . With generic per-file memory this is even more detached from
> process.
But this is exactly the use case here. See I do have the 1% which is
shared between processes, but 99% of the allocations only one process
has a reference to them.
So that wishful thinking that we can drop the last reference when we
kill this specific process is perfectly justified.
It can be that this doesn't fit all use cases for the shmem file, but it
certainly does for DRM and DMA-buf.
>> The difference is that this time the badness doesn't come from the memory
>> management subsystem, but rather from the I/O subsystem.
>>
>>> This is also the reason why I am not really fan of the per file
>>> badness because it adds a notion of resource that is not process bound
>>> in general so it will add all sorts of weird runtime corner cases which
>>> are impossible to anticipate [*]. Maybe that will work in some scenarios
>>> but definitely not something to be done by default without users opting
>>> into that and being aware of consequences.
>> Would a kernel command line option to control the behavior be helpful here?
> I am not sure what would be the proper way to control that that would be
> future extensible. Kernel command line is certainly and option but if we
> want to extend that to module like or eBPF interface then it wouldn't
> stand a future test very quickly.
Well kernel command lines are not really meant to be stable, aren't they?
Regards,
Christian.
WARNING: multiple messages have this Message-ID (diff)
From: "Christian König" <christian.koenig@amd.com>
To: Michal Hocko <mhocko@suse.com>
Cc: andrey.grodzovsky@amd.com, linux-mm@kvack.org,
nouveau@lists.freedesktop.org, intel-gfx@lists.freedesktop.org,
hughd@google.com, linux-kernel@vger.kernel.org,
amd-gfx@lists.freedesktop.org, linux-fsdevel@vger.kernel.org,
viro@zeniv.linux.org.uk, daniel@ffwll.ch,
"Christian König" <ckoenig.leichtzumerken@gmail.com>,
linux-tegra@vger.kernel.org, alexander.deucher@amd.com,
akpm@linux-foundation.org, linux-media@vger.kernel.org
Subject: Re: [PATCH 03/13] mm: shmem: provide oom badness for shmem files
Date: Wed, 15 Jun 2022 16:24:10 +0200 [thread overview]
Message-ID: <3ef8af8b-2dfa-79cf-e7cd-8a3e5ec20d6c@amd.com> (raw)
In-Reply-To: <Yqnba1E2FSRVUATY@dhcp22.suse.cz>
Am 15.06.22 um 15:15 schrieb Michal Hocko:
> On Wed 15-06-22 14:35:22, Christian König wrote:
> [...]
>> Even the classic mm_struct based accounting includes MM_SHMEMPAGES into the
>> badness. So accounting shared resources as badness to make a decision is
>> nothing new here.
> Yeah, it is nothing really new but it also doesn't mean it is an example
> worth following as this doesn't really work currently. Also please note
> that MM_SHMEMPAGES is counting at least something process specific as
> those pages are mapped in to the process (and with enough of wishful
> thinking unmapping can drop the last reference and free something up
> actually) . With generic per-file memory this is even more detached from
> process.
But this is exactly the use case here. See I do have the 1% which is
shared between processes, but 99% of the allocations only one process
has a reference to them.
So that wishful thinking that we can drop the last reference when we
kill this specific process is perfectly justified.
It can be that this doesn't fit all use cases for the shmem file, but it
certainly does for DRM and DMA-buf.
>> The difference is that this time the badness doesn't come from the memory
>> management subsystem, but rather from the I/O subsystem.
>>
>>> This is also the reason why I am not really fan of the per file
>>> badness because it adds a notion of resource that is not process bound
>>> in general so it will add all sorts of weird runtime corner cases which
>>> are impossible to anticipate [*]. Maybe that will work in some scenarios
>>> but definitely not something to be done by default without users opting
>>> into that and being aware of consequences.
>> Would a kernel command line option to control the behavior be helpful here?
> I am not sure what would be the proper way to control that that would be
> future extensible. Kernel command line is certainly and option but if we
> want to extend that to module like or eBPF interface then it wouldn't
> stand a future test very quickly.
Well kernel command lines are not really meant to be stable, aren't they?
Regards,
Christian.
next prev parent reply other threads:[~2022-06-15 14:24 UTC|newest]
Thread overview: 145+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-31 9:59 Per file OOM badness Christian König
2022-05-31 9:59 ` Christian König
2022-05-31 9:59 ` [Nouveau] " Christian König
2022-05-31 9:59 ` [PATCH 01/13] fs: add OOM badness callback to file_operatrations struct Christian König
2022-05-31 9:59 ` Christian König
2022-05-31 9:59 ` [Nouveau] " Christian König
2022-05-31 9:59 ` [PATCH 02/13] oom: take per file badness into account Christian König
2022-05-31 9:59 ` Christian König
2022-05-31 9:59 ` [Nouveau] " Christian König
2022-05-31 9:59 ` [PATCH 03/13] mm: shmem: provide oom badness for shmem files Christian König
2022-05-31 9:59 ` Christian König
2022-05-31 9:59 ` [Nouveau] " Christian König
2022-06-09 9:18 ` Michal Hocko
2022-06-09 9:18 ` [Nouveau] " Michal Hocko
2022-06-09 9:18 ` Michal Hocko
2022-06-09 9:18 ` [Intel-gfx] " Michal Hocko
2022-06-09 12:16 ` Christian König
2022-06-09 12:16 ` Christian König
2022-06-09 12:16 ` [Intel-gfx] " Christian König
2022-06-09 12:16 ` [Nouveau] " Christian König
2022-06-09 12:57 ` Michal Hocko
2022-06-09 12:57 ` [Nouveau] " Michal Hocko
2022-06-09 12:57 ` Michal Hocko
2022-06-09 12:57 ` [Intel-gfx] " Michal Hocko
2022-06-09 14:10 ` Christian König
2022-06-09 14:10 ` Christian König
2022-06-09 14:10 ` [Nouveau] " Christian König
2022-06-09 14:21 ` Michal Hocko
2022-06-09 14:21 ` [Nouveau] " Michal Hocko
2022-06-09 14:21 ` Michal Hocko
2022-06-09 14:21 ` [Intel-gfx] " Michal Hocko
2022-06-09 14:29 ` Christian König
2022-06-09 14:29 ` Christian König
2022-06-09 14:29 ` [Intel-gfx] " Christian König
2022-06-09 14:29 ` [Nouveau] " Christian König
2022-06-09 15:07 ` Michal Hocko
2022-06-09 15:07 ` [Nouveau] " Michal Hocko
2022-06-09 15:07 ` Michal Hocko
2022-06-09 15:07 ` [Intel-gfx] " Michal Hocko
2022-06-10 10:58 ` Christian König
2022-06-10 10:58 ` Christian König
2022-06-10 10:58 ` [Nouveau] " Christian König
2022-06-10 11:44 ` Michal Hocko
2022-06-10 11:44 ` [Nouveau] " Michal Hocko
2022-06-10 11:44 ` Michal Hocko
2022-06-10 11:44 ` [Intel-gfx] " Michal Hocko
2022-06-10 12:17 ` Christian König
2022-06-10 12:17 ` Christian König
2022-06-10 12:17 ` [Intel-gfx] " Christian König
2022-06-10 12:17 ` [Nouveau] " Christian König
2022-06-10 14:16 ` Michal Hocko
2022-06-10 14:16 ` [Nouveau] " Michal Hocko
2022-06-10 14:16 ` Michal Hocko
2022-06-10 14:16 ` [Intel-gfx] " Michal Hocko
2022-06-11 8:06 ` Christian König
2022-06-11 8:06 ` Christian König
2022-06-11 8:06 ` [Intel-gfx] " Christian König
2022-06-11 8:06 ` [Nouveau] " Christian König
2022-06-13 7:45 ` Michal Hocko
2022-06-13 7:45 ` [Nouveau] " Michal Hocko
2022-06-13 7:45 ` Michal Hocko
2022-06-13 7:45 ` [Intel-gfx] " Michal Hocko
2022-06-13 11:50 ` Christian König
2022-06-13 11:50 ` Christian König
2022-06-13 11:50 ` [Intel-gfx] " Christian König
2022-06-13 11:50 ` [Nouveau] " Christian König
2022-06-13 12:11 ` Michal Hocko
2022-06-13 12:11 ` [Nouveau] " Michal Hocko
2022-06-13 12:11 ` Michal Hocko
2022-06-13 12:11 ` [Intel-gfx] " Michal Hocko
2022-06-13 12:55 ` [Nouveau] " Christian König
2022-06-13 12:55 ` Christian König
2022-06-13 12:55 ` Christian König
2022-06-13 12:55 ` [Intel-gfx] " Christian König
2022-06-13 14:11 ` Michal Hocko
2022-06-13 14:11 ` [Nouveau] " Michal Hocko
2022-06-13 14:11 ` Michal Hocko
2022-06-13 14:11 ` Michal Hocko
2022-06-15 12:35 ` Christian König
2022-06-15 12:35 ` Christian König
2022-06-15 12:35 ` [Intel-gfx] " Christian König
2022-06-15 12:35 ` [Nouveau] " Christian König
2022-06-15 13:15 ` Michal Hocko
2022-06-15 13:15 ` [Nouveau] " Michal Hocko
2022-06-15 13:15 ` Michal Hocko
2022-06-15 13:15 ` [Intel-gfx] " Michal Hocko
2022-06-15 14:24 ` Christian König [this message]
2022-06-15 14:24 ` Christian König
2022-06-15 14:24 ` [Intel-gfx] " Christian König
2022-06-15 14:24 ` [Nouveau] " Christian König
2022-06-13 9:08 ` Michel Dänzer
2022-06-13 9:08 ` [Nouveau] " Michel Dänzer
2022-06-13 9:08 ` [Intel-gfx] " Michel Dänzer
2022-06-13 9:08 ` Michel Dänzer
2022-06-13 9:11 ` Christian König
2022-06-13 9:11 ` Christian König
2022-06-13 9:11 ` [Intel-gfx] " Christian König
2022-06-13 9:11 ` [Nouveau] " Christian König
2022-06-09 15:19 ` Felix Kuehling
2022-06-09 15:19 ` Felix Kuehling
2022-06-09 15:19 ` [Intel-gfx] " Felix Kuehling
2022-06-09 15:19 ` [Nouveau] " Felix Kuehling
2022-06-09 15:22 ` Christian König
2022-06-09 15:22 ` Christian König
2022-06-09 15:22 ` [Intel-gfx] " Christian König
2022-06-09 15:22 ` [Nouveau] " Christian König
2022-06-09 15:54 ` Michal Hocko
2022-06-09 15:54 ` [Nouveau] " Michal Hocko
2022-06-09 15:54 ` Michal Hocko
2022-06-09 15:54 ` [Intel-gfx] " Michal Hocko
2022-05-31 9:59 ` [PATCH 04/13] dma-buf: provide oom badness for DMA-buf files Christian König
2022-05-31 9:59 ` Christian König
2022-05-31 9:59 ` [Nouveau] " Christian König
2022-05-31 9:59 ` [PATCH 05/13] drm/gem: adjust per file OOM badness on handling buffers Christian König
2022-05-31 9:59 ` Christian König
2022-05-31 9:59 ` [Nouveau] " Christian König
2022-05-31 10:00 ` [PATCH 06/13] drm/gma500: use drm_oom_badness Christian König
2022-05-31 10:00 ` Christian König
2022-05-31 10:00 ` [Nouveau] " Christian König
2022-05-31 10:00 ` [PATCH 07/13] drm/amdgpu: Use drm_oom_badness for amdgpu Christian König
2022-05-31 10:00 ` Christian König
2022-05-31 10:00 ` [Nouveau] " Christian König
2022-05-31 10:00 ` [PATCH 08/13] drm/radeon: use drm_oom_badness Christian König
2022-05-31 10:00 ` Christian König
2022-05-31 10:00 ` [Nouveau] " Christian König
2022-05-31 10:00 ` [PATCH 09/13] drm/i915: " Christian König
2022-05-31 10:00 ` Christian König
2022-05-31 10:00 ` [Nouveau] " Christian König
2022-05-31 10:00 ` [PATCH 10/13] drm/nouveau: " Christian König
2022-05-31 10:00 ` Christian König
2022-05-31 10:00 ` [Nouveau] " Christian König
2022-05-31 10:00 ` [PATCH 11/13] drm/omap: " Christian König
2022-05-31 10:00 ` Christian König
2022-05-31 10:00 ` [Nouveau] " Christian König
2022-05-31 10:00 ` [PATCH 12/13] drm/vmwgfx: " Christian König
2022-05-31 10:00 ` Christian König
2022-05-31 10:00 ` [Nouveau] " Christian König
2022-05-31 10:00 ` [PATCH 13/13] drm/tegra: " Christian König
2022-05-31 10:00 ` Christian König
2022-05-31 10:00 ` [Nouveau] " Christian König
2022-05-31 22:00 ` Per file OOM badness Alex Deucher
2022-05-31 22:00 ` Alex Deucher
2022-05-31 22:00 ` [Intel-gfx] " Alex Deucher
2022-05-31 22:00 ` Alex Deucher
2022-05-31 22:00 ` [Nouveau] " Alex Deucher
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