From: Bill Huey (hui) <billh@gnuppy.monkey.org>
To: "Martin J. Bligh" <mbligh@mbligh.org>
Cc: Christoph Hellwig <hch@infradead.org>,
Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Andrew Morton <akpm@osdl.org>,
linux-kernel@vger.kernel.org, Dipankar Sarma <dipankar@hill9.org>,
"Bill Huey (hui)" <billh@gnuppy.monkey.org>
Subject: Re: lockmeter
Date: Sun, 28 Jan 2007 10:01:32 -0800 [thread overview]
Message-ID: <20070128180132.GA1647@gnuppy.monkey.org> (raw)
In-Reply-To: <45BCDF88.2020504@mbligh.org>
On Sun, Jan 28, 2007 at 09:38:16AM -0800, Martin J. Bligh wrote:
> Christoph Hellwig wrote:
> >On Sun, Jan 28, 2007 at 08:52:25AM -0800, Martin J. Bligh wrote:
> >>Mmm. not wholly convinced that's true. Whilst i don't have lockmeter
> >>stats to hand, the heavy time in __d_lookup seems to indicate we may
> >>still have a problem to me. I guess we could move the spinlocks out
> >>of line again to test this fairly easily (or get lockmeter upstream).
> >
> >We definitly should get lockmeter in. Does anyone volunteer for doing
> >the cleanup and merged?
>
> On second thoughts .. I don't think it'd actually work for this since
> the locks aren't global. Not that it shouldn't be done anyway, but ...
>
> ISTR we still thought dcache scalability was a significant problem last
> time anyone looked at it seriously - just never got fixed. Dipankar?
My lock stat stuff shows dcache to a be a problem under -rt as well. It
is keyed off the same mechanism as lockdep. It's pretty heavily hit
under even normal loads relative to other kinds of lock overhead even
for casual file operations on a 2x system. I can't imagine how lousy
it's going to be under real load on a 8x or higher machine.
However, this pathc is -rt only and spinlock times are meaningless under
it because of preemptiblity.
bill
next prev parent reply other threads:[~2007-01-28 18:03 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-01-28 11:51 [PATCH 0/7] breaking the global file_list_lock Peter Zijlstra
2007-01-28 11:51 ` [PATCH 1/7] lockdep: lock_set_subclass - reset a held locks subclass Peter Zijlstra
2007-01-28 11:51 ` [PATCH 3/7] barrier: a scalable synchonisation barrier Peter Zijlstra
2007-01-28 14:39 ` Christoph Hellwig
2007-01-28 15:24 ` Ingo Molnar
2007-01-28 15:34 ` Christoph Hellwig
2007-01-31 19:12 ` Paul E. McKenney
2007-01-31 21:13 ` Oleg Nesterov
2007-01-31 21:30 ` Oleg Nesterov
2007-01-31 21:48 ` Peter Zijlstra
2007-01-31 23:32 ` Paul E. McKenney
2007-02-01 0:03 ` Peter Zijlstra
2007-02-01 0:48 ` Paul E. McKenney
2007-02-01 16:00 ` Oleg Nesterov
2007-02-01 21:38 ` Paul E. McKenney
2007-02-02 11:56 ` Oleg Nesterov
2007-02-02 12:01 ` Peter Zijlstra
2007-02-02 17:13 ` Paul E. McKenney
2007-02-03 16:38 ` Oleg Nesterov
2007-02-04 0:23 ` Paul E. McKenney
2007-02-04 3:24 ` Alan Stern
2007-02-04 5:46 ` Paul E. McKenney
2007-01-28 11:51 ` [PATCH 4/7] fs: break the file_list_lock for sb->s_files Peter Zijlstra
2007-01-28 14:43 ` Christoph Hellwig
2007-01-28 15:21 ` Ingo Molnar
2007-01-28 15:30 ` Christoph Hellwig
2007-01-28 15:32 ` Peter Zijlstra
2007-01-28 15:36 ` Christoph Hellwig
2007-01-28 15:44 ` Ingo Molnar
2007-01-28 16:25 ` Bill Huey
2007-01-28 11:51 ` [PATCH 5/7] fs: restore previous sb->s_files iteration semantics Peter Zijlstra
2007-01-28 11:51 ` [PATCH 6/7] schedule_on_each_cpu_wq() Peter Zijlstra
2007-01-28 11:51 ` [PATCH 7/7] fs: fixup filevec_add_drain_all Peter Zijlstra
2007-01-28 12:16 ` [PATCH 8/7] fs: free_write_pipe() fix Peter Zijlstra
2007-01-28 14:43 ` [PATCH 0/7] breaking the global file_list_lock Christoph Hellwig
2007-01-28 15:11 ` Christoph Hellwig
2007-01-28 15:29 ` Peter Zijlstra
2007-01-28 15:33 ` Christoph Hellwig
2007-01-29 13:32 ` Stephen Smalley
2007-01-29 18:02 ` Christoph Hellwig
2007-01-28 15:24 ` Ingo Molnar
2007-01-28 16:52 ` Martin J. Bligh
2007-01-28 17:04 ` lockmeter Christoph Hellwig
2007-01-28 17:38 ` lockmeter Martin J. Bligh
2007-01-28 18:01 ` Bill Huey [this message]
2007-01-28 19:26 ` lockmeter Ingo Molnar
2007-01-28 21:17 ` lockmeter Ingo Molnar
2007-01-29 5:27 ` lockmeter Bill Huey
2007-01-29 10:26 ` lockmeter Bill Huey
2007-01-29 1:08 ` lockmeter Arjan van de Ven
2007-01-29 1:12 ` lockmeter Martin J. Bligh
2007-01-28 18:41 ` [PATCH 0/7] breaking the global file_list_lock Ingo Molnar
2007-01-28 20:38 ` Christoph Hellwig
2007-01-28 21:05 ` Ingo Molnar
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