From: Olof Johansson <olof@lixom.net>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: npiggin@suse.de, linuxppc-dev@ozlabs.org,
Anton Blanchard <anton@samba.org>
Subject: Re: [PATCH 6/6] powerpc: Use lwsync for acquire barrier if CPU supports it
Date: Tue, 16 Feb 2010 00:07:58 -0600 [thread overview]
Message-ID: <20100216060758.GA12891@lixom.net> (raw)
In-Reply-To: <1266293943.16346.169.camel@pasglop>
On Tue, Feb 16, 2010 at 03:19:03PM +1100, Benjamin Herrenschmidt wrote:
> On Mon, 2010-02-15 at 22:22 -0600, Olof Johansson wrote:
> >
> > Turns out this one hurts PA6T performance quite a bit, lwsync seems to be
> > significantly more expensive there. I see a 25% drop in the microbenchmark
> > doing pthread_lock/unlock loops on two cpus.
> >
> > Taking out the CPU_FTR_LWSYNC will solve it, it's a bit unfortunate since
> > the sync->lwsync changes definitely still can, and should, be done.
>
> So we should use a different feature bit. No biggie. If needed we can
> split them more anyways.
Yeah, fine with me.
-Olof
next prev parent reply other threads:[~2010-02-16 6:03 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-10 10:57 [PATCH 1/6] powerpc: Use lwarx hint in spinlocks Anton Blanchard
2010-02-10 11:02 ` [PATCH 2/6] powerpc: Use lwarx/ldarx hint in bit locks Anton Blanchard
2010-02-10 11:03 ` [PATCH 3/6] powerpc: Convert open coded native hashtable bit lock Anton Blanchard
2010-02-10 11:04 ` [PATCH 4/6] powerpc: Rename LWSYNC_ON_SMP to PPC_RELEASE_BARRIER, ISYNC_ON_SMP to PPC_ACQUIRE_BARRIER Anton Blanchard
2010-02-10 11:07 ` [PATCH 5/6] powerpc: Fix lwsync patching code on 64bit Anton Blanchard
2010-02-10 11:10 ` [PATCH 6/6] powerpc: Use lwsync for acquire barrier if CPU supports it Anton Blanchard
2010-02-11 7:09 ` Nick Piggin
2010-02-17 9:43 ` Anton Blanchard
2010-02-17 10:41 ` Nick Piggin
2010-02-17 12:12 ` Benjamin Herrenschmidt
2010-02-16 4:22 ` Olof Johansson
2010-02-16 4:19 ` Benjamin Herrenschmidt
2010-02-16 6:07 ` Olof Johansson [this message]
2010-03-19 1:08 ` [PATCH 4/6] powerpc: Rename LWSYNC_ON_SMP to PPC_RELEASE_BARRIER, ISYNC_ON_SMP to PPC_ACQUIRE_BARRIER Nick Piggin
2010-03-19 1:36 ` Benjamin Herrenschmidt
2010-02-11 6:56 ` [PATCH 1/6] powerpc: Use lwarx hint in spinlocks Nick Piggin
2010-02-17 9:37 ` Anton Blanchard
2010-02-17 10:22 ` Nick Piggin
2010-02-16 4:16 ` Olof Johansson
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