[Bug 93301] ns2_linux32: radeon VM fault on Hawaii (+mmap errors) - bugzilla-daemon

From: bugzilla-daemon@freedesktop.org
To: dri-devel@lists.freedesktop.org
Subject: [Bug 93301] ns2_linux32: radeon VM fault on Hawaii (+mmap errors)
Date: Wed, 09 Dec 2015 14:35:13 +0000	[thread overview]
Message-ID: <bug-93301-502-lol22llWX6@http.bugs.freedesktop.org/> (raw)
In-Reply-To: <bug-93301-502@http.bugs.freedesktop.org/>

[-- Attachment #1.1: Type: text/plain, Size: 852 bytes --]

https://bugs.freedesktop.org/show_bug.cgi?id=93301

--- Comment #14 from Marek Olšák <maraeo@gmail.com> ---
No, Hawaii doesn't have DCC.

The issue can indeed be that there is not enough address space. Mesa doesn't
unmap most buffers, because mmap is a very costly operation. Such buffers are
only unmapped when destroyed. This is obviously a problem on 32-bit. Possible
solutions:

1) Always unmap buffers at appropriate places. This can have a significant
performance cost in CPU-bound apps.

2) Clear pb_cache on mmap failure and try mmap again.

(pb_cache typically contains staging buffers, which are always mapped.
Therefore, pb_cache completely hides allocation, GPU mmap, and CPU mmap
overhead, but it also contributes to address space usage.)

-- 
You are receiving this mail because:
You are the assignee for the bug.

[-- Attachment #1.2: Type: text/html, Size: 1644 bytes --]

[-- Attachment #2: Type: text/plain, Size: 159 bytes --]

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