From: Dinakar Guniguntala <dino@in.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@elte.hu>, david singleton <dsingleton@mvista.com>
Subject: Perf degradation from -rt14 onwards
Date: Fri, 2 Dec 2005 02:12:27 +0530 [thread overview]
Message-ID: <20051201204227.GA16035@in.ibm.com> (raw)
I was wondering why the following change was made from -rt14
onwards.
@@ -1634,7 +1531,7 @@ asmlinkage long sys_futex(u32 __user *ua
int val3)
{
struct timespec t;
- unsigned long timeout = MAX_SCHEDULE_TIMEOUT;
+ unsigned long timeout = 0;
This was introduced in patch-2.6.14-rt13-rf3 by David.
This seems to return spurious -ETIMEDOUT errors even in the
non-robust code and results in userspace (glibc) retrying
several mutex operations before it succeeds. I was chasing
down a degradation of performance of some testcases and was
able to fix those by reverting this change back.
-Dinakar
next reply other threads:[~2005-12-01 20:22 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-12-01 20:42 Dinakar Guniguntala [this message]
2005-12-01 20:59 ` Perf degradation from -rt14 onwards David Singleton
2005-12-01 21:21 ` Ingo Molnar
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