From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon@freedesktop.org Subject: [Bug 93301] ns2_linux32: radeon VM fault on Hawaii (+mmap errors) Date: Wed, 09 Dec 2015 14:35:13 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1680056769==" Return-path: Received: from culpepper.freedesktop.org (unknown [131.252.210.165]) by gabe.freedesktop.org (Postfix) with ESMTP id AB9006E180 for ; Wed, 9 Dec 2015 06:35:13 -0800 (PST) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org --===============1680056769== Content-Type: multipart/alternative; boundary="1449671713.A30C3F0.23316"; charset="UTF-8" --1449671713.A30C3F0.23316 Date: Wed, 9 Dec 2015 14:35:13 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable https://bugs.freedesktop.org/show_bug.cgi?id=3D93301 --- Comment #14 from Marek Ol=C5=A1=C3=A1k --- 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 a= re only unmapped when destroyed. This is obviously a problem on 32-bit. Possib= le 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.) --=20 You are receiving this mail because: You are the assignee for the bug. --1449671713.A30C3F0.23316 Date: Wed, 9 Dec 2015 14:35:13 +0000 MIME-Version: 1.0 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

Commen= t # 14 on bug 93301<= /a> from Marek Ol=C5=A1=C3=A1k 
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 a=
re
only unmapped when destroyed. This is obviously a problem on 32-bit. Possib=
le
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: =20=20=20=20=20=20
  • You are the assignee for the bug.
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