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  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]
Date:	Thu, 4 Jan 2007 00:12:50 -0800
From:	Bill Huey (hui) <>
To:	"Chen, Tim C" <>
Cc:	Ingo Molnar <>,,
	"Siddha, Suresh B" <>,
	Peter Zijlstra <>,
	Steven Rostedt <>,
	Thomas Gleixner <>,
	Daniel Walker <>,
	"Bill Huey (hui)" <>
Subject: Re: [PATCH] lock stat for -rt 2.6.20-rc2-rt2.2.lock_stat.patch

On Wed, Jan 03, 2007 at 06:14:11PM -0800, Chen, Tim C wrote:
> Bill Huey (hui) wrote:
> > If you can rerun it and post the results, it'll hopefully show the
> > behavior of that lock acquisition better.
> Here's the run with fix to produce correct statistics.
> Tim
> @contention events = 848858
> @failure_events = 10
> @lookup_failed_scope = 175
> @lookup_failed_static = 47
> @static_found = 17
> [112584, 150, 6 -- 256, 0]              {init, kernel/futex.c, 2781}
> [597012, 183895, 136277 -- 9546, 0]             {mm_init, kernel/fork.c,
> 369}

Interesting. The second column means that those can be adaptively spun
on to prevent the blocking from happening. That's roughly 1/3rd of the
blocking events that happen (second/first). Something like that would
help out, but the problem is that contention on that lock in the first

Also, Linux can do a hell of a lot of context switches per second. Is
the number of total contentions (top figure) in that run consistent with
the performance degradation ? and how much the reduction of those events
by 1/3rd would help out with the benchmark ? Those are the questions in
my mind at this moment.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists