From: "Christian König" <ckoenig.leichtzumerken-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
To: Harry Wentland <harry.wentland-5C7GfCeVMHo@public.gmane.org>,
Shirish S <shirish.s-5C7GfCeVMHo@public.gmane.org>,
amd-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org
Subject: Re: [PATCH] drm/amd/display: avoid sleeping in atomic context while creating new context or state
Date: Thu, 31 May 2018 20:05:42 +0200 [thread overview]
Message-ID: <56590c3a-6f96-17b1-a3c3-c3159bf5b313@gmail.com> (raw)
In-Reply-To: <1b831a0f-3d54-2b07-12f8-b1ddda9007f6-5C7GfCeVMHo@public.gmane.org>
Am 30.05.2018 um 18:03 schrieb Harry Wentland:
> On 2018-05-30 06:17 AM, Shirish S wrote:
>> This patch fixes the warning messages that are caused due to calling
>> sleep in atomic context as below:
>>
>> BUG: sleeping function called from invalid context at mm/slab.h:419
>> in_atomic(): 1, irqs_disabled(): 1, pid: 5, name: kworker/u4:0
>> CPU: 1 PID: 5 Comm: kworker/u4:0 Tainted: G W 4.14.35 #941
>> Workqueue: events_unbound commit_work
>> Call Trace:
>> dump_stack+0x4d/0x63
>> ___might_sleep+0x11f/0x12e
>> kmem_cache_alloc_trace+0x41/0xea
>> dc_create_state+0x1f/0x30
>> dc_commit_updates_for_stream+0x73/0x4cf
>> ? amdgpu_get_crtc_scanoutpos+0x82/0x16b
>> amdgpu_dm_do_flip+0x239/0x298
>> amdgpu_dm_commit_planes.isra.23+0x379/0x54b
>> ? dc_commit_state+0x3da/0x404
>> amdgpu_dm_atomic_commit_tail+0x4fc/0x5d2
>> ? wait_for_common+0x5b/0x69
>> commit_tail+0x42/0x64
>> process_one_work+0x1b0/0x314
>> worker_thread+0x1cb/0x2c1
>> ? create_worker+0x1da/0x1da
>> kthread+0x156/0x15e
>> ? kthread_flush_work+0xea/0xea
>> ret_from_fork+0x22/0x40
>>
>> Signed-off-by: Shirish S <shirish.s@amd.com>
>> ---
>> drivers/gpu/drm/amd/display/dc/core/dc.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
>> index 33149ed..d62206f 100644
>> --- a/drivers/gpu/drm/amd/display/dc/core/dc.c
>> +++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
>> @@ -588,7 +588,7 @@ static void disable_dangling_plane(struct dc *dc, struct dc_state *context)
>>
>> struct dc *dc_create(const struct dc_init_data *init_params)
>> {
>> - struct dc *dc = kzalloc(sizeof(*dc), GFP_KERNEL);
>> + struct dc *dc = kzalloc(sizeof(*dc), GFP_ATOMIC);
> Are you sure this one can be called in atomic_context?
>
> If so then everything in consstruct() would also need GFP_ATOMIC.
Well the backtrace is quite obvious, but I agree that change still looks
fishy to me as well.
Using GFP_ATOMIC should only be a last resort when nothing else helps,
but here it looks more like we misuse a spinlock where a mutex or
semaphore would be more appropriate.
Where exactly becomes the context atomic in the call trace?
Christian.
>
> Harry
>
>> unsigned int full_pipe_count;
>>
>> if (NULL == dc)
>> @@ -937,7 +937,7 @@ bool dc_post_update_surfaces_to_stream(struct dc *dc)
>> struct dc_state *dc_create_state(void)
>> {
>> struct dc_state *context = kzalloc(sizeof(struct dc_state),
>> - GFP_KERNEL);
>> + GFP_ATOMIC);
>>
>> if (!context)
>> return NULL;
>>
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
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next prev parent reply other threads:[~2018-05-31 18:05 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-30 10:17 [PATCH] drm/amd/display: avoid sleeping in atomic context while creating new context or state Shirish S
[not found] ` <1527675436-24022-1-git-send-email-shirish.s-5C7GfCeVMHo@public.gmane.org>
2018-05-30 16:03 ` Harry Wentland
[not found] ` <1b831a0f-3d54-2b07-12f8-b1ddda9007f6-5C7GfCeVMHo@public.gmane.org>
2018-05-31 10:01 ` S, Shirish
2018-05-31 18:05 ` Christian König [this message]
[not found] ` <56590c3a-6f96-17b1-a3c3-c3159bf5b313-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-06-01 9:56 ` S, Shirish
[not found] ` <67617d8b-65ee-1bfc-7937-14f534cc98b8-5C7GfCeVMHo@public.gmane.org>
2018-06-01 10:10 ` Christian König
2018-06-07 14:44 ` Michel Dänzer
[not found] ` <3ed3bc96-4218-de1f-ba0a-1e4102883438-otUistvHUpPR7s880joybQ@public.gmane.org>
2018-06-07 14:46 ` Harry Wentland
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