From: "Christian König" <ckoenig.leichtzumerken@gmail.com>
To: Thorsten Leemhuis <regressions@leemhuis.info>,
Ben Skeggs <skeggsb@gmail.com>
Cc: David Airlie <airlied@linux.ie>,
ML nouveau <nouveau@lists.freedesktop.org>,
ML dri-devel <dri-devel@lists.freedesktop.org>,
dmoulding@me.com, Ben Skeggs <bskeggs@redhat.com>,
Stefan Fritsch <sf@sfritsch.de>
Subject: Re: [Nouveau] [PATCH] drm/nouveau: wait for the exclusive fence after the shared ones v2
Date: Tue, 21 Dec 2021 11:20:50 +0100 [thread overview]
Message-ID: <0e0afdc2-513e-86d9-78ca-4c433e3da5a8@gmail.com> (raw)
In-Reply-To: <c0e77c90-ad42-29ed-7bc6-68f45dbbcfc2@leemhuis.info>
Am 21.12.21 um 11:11 schrieb Thorsten Leemhuis:
> Hi, this is your Linux kernel regression tracker speaking.
>
> CCing Dave and Daniel.
>
> On 15.12.21 23:32, Ben Skeggs wrote:
>> On Tue, 14 Dec 2021 at 19:19, Christian König
>> <ckoenig.leichtzumerken@gmail.com> wrote:
>>> Am 11.12.21 um 10:59 schrieb Stefan Fritsch:
>>>> On 09.12.21 11:23, Christian König wrote:
>>>>> Always waiting for the exclusive fence resulted on some performance
>>>>> regressions. So try to wait for the shared fences first, then the
>>>>> exclusive fence should always be signaled already.
>>>>>
>>>>> v2: fix incorrectly placed "(", add some comment why we do this.
>>>>>
>>>>> Signed-off-by: Christian König <christian.koenig@amd.com>
>>>> Tested-by: Stefan Fritsch <sf@sfritsch.de>
>>> Thanks.
>>>
>>>> Please also add a cc for linux-stable, so that this is fixed in 5.15.x
>>> Sure, but I still need some acked-by or rb from one of the Nouveau guys.
>>> So gentle ping on that.
>> Acked-by: Ben Skeggs <bskeggs@redhat.com>
> What's the status of this patch? I checked a few git trees, but either
> it's not there or it missed it.
You missed it. I've pushed it to drm-misc-fixes about 2 hours ago:
https://cgit.freedesktop.org/drm/drm-misc/log/?h=drm-misc-fixes
Regards,
Christian.
>
> Reminder, it's a regression already introduced in v5.15, hence all users
> of the current stable kernel are affected by it, so it would be nice to
> get the fix on its way now that Ben acked it and Dan tested it.
>
> Ciao, Thorsten
>
> P.S.: As a Linux kernel regression tracker I'm getting a lot of reports
> on my table. I can only look briefly into most of them. Unfortunately
> therefore I sometimes will get things wrong or miss something important.
> I hope that's not the case here; if you think it is, don't hesitate to
> tell me about it in a public reply. That's in everyone's interest, as
> what I wrote above might be misleading to everyone reading this; any
> suggestion I gave thus might sent someone reading this down the wrong
> rabbit hole, which none of us wants.
>
> BTW, I have no personal interest in this issue, which is tracked using
> regzbot, my Linux kernel regression tracking bot
> (https://linux-regtracking.leemhuis.info/regzbot/). I'm only posting
> this mail to get things rolling again and hence don't need to be CC on
> all further activities wrt to this regression.
>
> #regzbot poke
>
>>>>> ---
>>>>> drivers/gpu/drm/nouveau/nouveau_fence.c | 28 +++++++++++++------------
>>>>> 1 file changed, 15 insertions(+), 13 deletions(-)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/nouveau/nouveau_fence.c
>>>>> b/drivers/gpu/drm/nouveau/nouveau_fence.c
>>>>> index 05d0b3eb3690..0ae416aa76dc 100644
>>>>> --- a/drivers/gpu/drm/nouveau/nouveau_fence.c
>>>>> +++ b/drivers/gpu/drm/nouveau/nouveau_fence.c
>>>>> @@ -353,15 +353,22 @@ nouveau_fence_sync(struct nouveau_bo *nvbo,
>>>>> struct nouveau_channel *chan, bool e
>>>>> if (ret)
>>>>> return ret;
>>>>> - }
>>>>> - fobj = dma_resv_shared_list(resv);
>>>>> - fence = dma_resv_excl_fence(resv);
>>>>> + fobj = NULL;
>>>>> + } else {
>>>>> + fobj = dma_resv_shared_list(resv);
>>>>> + }
>>>>> - if (fence) {
>>>>> + /* Waiting for the exclusive fence first causes performance
>>>>> regressions
>>>>> + * under some circumstances. So manually wait for the shared
>>>>> ones first.
>>>>> + */
>>>>> + for (i = 0; i < (fobj ? fobj->shared_count : 0) && !ret; ++i) {
>>>>> struct nouveau_channel *prev = NULL;
>>>>> bool must_wait = true;
>>>>> + fence = rcu_dereference_protected(fobj->shared[i],
>>>>> + dma_resv_held(resv));
>>>>> +
>>>>> f = nouveau_local_fence(fence, chan->drm);
>>>>> if (f) {
>>>>> rcu_read_lock();
>>>>> @@ -373,20 +380,13 @@ nouveau_fence_sync(struct nouveau_bo *nvbo,
>>>>> struct nouveau_channel *chan, bool e
>>>>> if (must_wait)
>>>>> ret = dma_fence_wait(fence, intr);
>>>>> -
>>>>> - return ret;
>>>>> }
>>>>> - if (!exclusive || !fobj)
>>>>> - return ret;
>>>>> -
>>>>> - for (i = 0; i < fobj->shared_count && !ret; ++i) {
>>>>> + fence = dma_resv_excl_fence(resv);
>>>>> + if (fence) {
>>>>> struct nouveau_channel *prev = NULL;
>>>>> bool must_wait = true;
>>>>> - fence = rcu_dereference_protected(fobj->shared[i],
>>>>> - dma_resv_held(resv));
>>>>> -
>>>>> f = nouveau_local_fence(fence, chan->drm);
>>>>> if (f) {
>>>>> rcu_read_lock();
>>>>> @@ -398,6 +398,8 @@ nouveau_fence_sync(struct nouveau_bo *nvbo,
>>>>> struct nouveau_channel *chan, bool e
>>>>> if (must_wait)
>>>>> ret = dma_fence_wait(fence, intr);
>>>>> +
>>>>> + return ret;
>>>>> }
>>>>> return ret;
next prev parent reply other threads:[~2021-12-21 10:20 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-09 10:23 [PATCH] drm/nouveau: wait for the exclusive fence after the shared ones v2 Christian König
2021-12-10 9:06 ` [Nouveau] " Thorsten Leemhuis
2021-12-11 9:59 ` Stefan Fritsch
2021-12-14 9:19 ` Christian König
2021-12-15 22:32 ` [Nouveau] " Ben Skeggs
2021-12-21 10:11 ` Thorsten Leemhuis
2021-12-21 10:20 ` Christian König [this message]
2021-12-20 19:17 ` Dan Moulding
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=0e0afdc2-513e-86d9-78ca-4c433e3da5a8@gmail.com \
--to=ckoenig.leichtzumerken@gmail.com \
--cc=airlied@linux.ie \
--cc=bskeggs@redhat.com \
--cc=dmoulding@me.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=nouveau@lists.freedesktop.org \
--cc=regressions@leemhuis.info \
--cc=sf@sfritsch.de \
--cc=skeggsb@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).