linux-kernel - Re: DRM lock ordering fix series

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87ocvnmhqx.fsf@basil.nowhere.org>
Date:	Fri, 27 Mar 2009 10:34:30 +0100
From:	Andi Kleen <andi@...stfloor.org>
To:	Eric Anholt <eric@...olt.net>
Cc:	linux-kernel@...r.kernel.org, dri-devel@...ts.sourceforge.net
Subject: Re: DRM lock ordering fix series

Eric Anholt <eric@...olt.net> writes:

> Here's hopefully the final attempt at the lock ordering fix for GEM.  The
> problem was introduced in .29 with the GTT mapping support.  We hashed out
> a few potential fixes on the mailing list and at OSTS.  Peter's plan was
> to use get_user_pages, but it has significant CPU overhead (10% cost to text
> rendering, though part of that is due to some dumb userland code.  But it's
> dumb userland code we're all running).


You are aware that there is a fast path now (get_user_pages_fast) which
is significantly faster? (but has some limitations)

-Andi

-- 
ak@...ux.intel.com -- Speaking for myself only.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/