From: Peter Zijlstra <peterz@infradead.org>
To: "Christian König" <christian.koenig@amd.com>
Cc: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
linux-kernel@vger.kernel.org, dev@mblankhorst.nl,
chris@chris-wilson.co.uk
Subject: Re: [PATCH 1/4] locking/ww_mutex: add ww_mutex_is_owned_by function v3
Date: Tue, 20 Feb 2018 15:54:13 +0100 [thread overview]
Message-ID: <20180220145413.GF25201@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <b625cbca-c05a-afd1-fe97-a7a0760383c1@amd.com>
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.
Chris, Maarten, do either one of you remember?
I'm thinking that if we do acquire the trylock, the thing should join
the ctx such that a subsequent contending mutex_lock() can ww right.
next prev parent reply other threads:[~2018-02-20 14:54 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
2018-02-20 12:58 ` [PATCH 2/4] drm/amdgpu: use new ww_mutex_is_owned_by function Christian König
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
2018-02-23 9:46 ` He, Roger
2018-02-23 12:05 ` Christian König
2018-02-24 3:36 ` He, Roger
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
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
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 [this message]
2018-02-20 15:05 ` Christian König
2018-02-20 15:21 ` Peter Zijlstra
2018-02-20 23:56 ` Daniel Vetter
2018-02-21 10:54 ` Maarten Lankhorst
2018-02-21 11:50 ` Christian König
2018-02-21 21:10 ` Emil Velikov
2018-02-20 14:02 ` Daniel Vetter
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