dri-devel Archive on lore.kernel.org
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: christian.koenig@amd.com
Cc: dev@mblankhorst.nl, amd-gfx@lists.freedesktop.org,
	dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/4] locking/ww_mutex: add ww_mutex_is_owned_by function v3
Date: Tue, 20 Feb 2018 16:21:58 +0100	[thread overview]
Message-ID: <20180220152158.GH25201@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <2dac8ec9-c54a-7dd1-af4e-62f2bc1a959c@gmail.com>

On Tue, Feb 20, 2018 at 04:05:49PM +0100, Christian König wrote:
> Am 20.02.2018 um 15:54 schrieb Peter Zijlstra:
> > On Tue, Feb 20, 2018 at 03:34:07PM +0100, Christian König wrote:
> > > > OK, but neither case would in fact need the !ctx case right? That's just
> > > > there for completeness sake?
> > > Unfortunately not. TTM uses trylock to lock BOs which are about to be
> > > evicted to make room for all the BOs locked with a ctx.
> > > 
> > > I need to be able to distinct between the BOs which are trylocked and those
> > > which are locked with a ctx.
> > > 
> > > Writing this I actually noticed the current version is buggy, cause even
> > > when we check the mutex owner we still need to make sure that the ctx in the
> > > lock is NULL.
> > Hurm... I can't remember why trylocks behave like that, and it seems
> > rather unfortunate / inconsistent.
> 
> Actually for me that is rather fortunate, cause I need to distinct between
> the locks acquired through trylock and lock.

I suppose that would always be possible using:
ww_mutex_trylock(.ctx=NULL), and it could be that there simply weren't
any immediate uses for a !NULL trylock and it was thus not implemented.

But that is all very long ago..

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

  reply	other threads:[~2018-02-20 15:21 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-20 12:58 [PATCH 1/4] locking/ww_mutex: add ww_mutex_is_owned_by function v3 Christian König
     [not found] ` <20180220125829.27060-1-christian.koenig-5C7GfCeVMHo@public.gmane.org>
2018-02-20 12:58   ` [PATCH 2/4] drm/amdgpu: use new ww_mutex_is_owned_by function Christian König
     [not found]     ` <20180220125829.27060-2-christian.koenig-5C7GfCeVMHo@public.gmane.org>
2018-02-23  9:48       ` He, Roger
2018-02-20 12:58   ` [PATCH 3/4] drm/ttm: handle already locked BOs during eviction and swapout Christian König
     [not found]     ` <20180220125829.27060-3-christian.koenig-5C7GfCeVMHo@public.gmane.org>
2018-02-23  9:46       ` He, Roger
2018-02-23 12:05         ` Christian König
     [not found]           ` <6eadbbea-8eca-a1ab-93bb-d37ae6e5f29d-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-02-24  3:36             ` He, Roger
     [not found]               ` <MWHPR1201MB01278E573419210283D68640FDC30-3iK1xFAIwjq9imrIu4W8xGrFom/aUZj6nBOFsp37pqbUKgpGm//BTAC/G2K4zDHf@public.gmane.org>
2018-02-24  3:46                 ` He, Roger
2018-02-20 12:58   ` [PATCH 4/4] drm/ttm: keep BOs reserved until end of eviction Christian König
     [not found]     ` <20180220125829.27060-4-christian.koenig-5C7GfCeVMHo@public.gmane.org>
2018-02-23  9:29       ` He, Roger
2018-02-20 13:12 ` [PATCH 1/4] locking/ww_mutex: add ww_mutex_is_owned_by function v3 Peter Zijlstra
     [not found]   ` <20180220131253.GF25314-Nxj+rRp3nVydTX5a5knrm8zTDFooKrT+cvkQGrU6aU0@public.gmane.org>
2018-02-20 13:26     ` Christian König
2018-02-20 13:57       ` Peter Zijlstra
2018-02-20 14:34         ` Christian König
2018-02-20 14:54           ` Peter Zijlstra
2018-02-20 15:05             ` Christian König
2018-02-20 15:21               ` Peter Zijlstra [this message]
2018-02-20 23:56                 ` Daniel Vetter
     [not found]                   ` <20180220235621.GD22199-dv86pmgwkMBes7Z6vYuT8azUEOm+Xw19@public.gmane.org>
2018-02-21 10:54                     ` Maarten Lankhorst
     [not found]                       ` <9d782099-567f-38cb-391a-3c2a50cd5edd-FcfepWsj2zOByvU0x3ry2g@public.gmane.org>
2018-02-21 11:50                         ` Christian König
2018-02-21 21:10     ` Emil Velikov
2018-02-20 14:02 ` Daniel Vetter

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=20180220152158.GH25201@hirez.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=amd-gfx@lists.freedesktop.org \
    --cc=christian.koenig@amd.com \
    --cc=dev@mblankhorst.nl \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=linux-kernel@vger.kernel.org \
    /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