From: Ingo Molnar <mingo@elte.hu>
To: Zachary Amsden <zamsden@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>,
"H. Peter Anvin" <hpa@zytor.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, Avi Kivity <avi@redhat.com>
Subject: Re: [PATCH] x86 rwsem optimization extreme
Date: Thu, 18 Feb 2010 11:55:06 +0100 [thread overview]
Message-ID: <20100218105506.GA9944@elte.hu> (raw)
In-Reply-To: <4B7CF95A.4040706@redhat.com>
* Zachary Amsden <zamsden@redhat.com> wrote:
> >
> >Zachary Amsden<zamsden@redhat.com> writes
> >>Incidentally, the cost of putting all the rwsem code inline, using the
> >>straightforward approach, for git-tip, using defconfig on x86_64 is
> >>3565 bytes / 20971778 bytes total, or 0.0168%, using gcc 4.4.3.
> >The nice advantage of putting lock code inline is that it gets
> >accounted to the caller in all profilers.
> >
> >-Andi
> >
>
> Unfortunately, only for the uncontended case. The hot case still ends up
> in a call to the lock text section.
Nor is it really true that it's 'a problem for profilers' - call graph
recording works just fine, in fact it can be better for a call-graph record
if the locking sites are not sprinkled around the kernel and inlined.
Ingo
prev parent reply other threads:[~2010-02-18 10:55 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-17 21:58 [PATCH] x86 rwsem optimization extreme Zachary Amsden
2010-02-17 22:10 ` Linus Torvalds
2010-02-17 22:29 ` H. Peter Anvin
2010-02-17 23:29 ` H. Peter Anvin
2010-02-18 1:03 ` Zachary Amsden
2010-02-18 1:53 ` Linus Torvalds
2010-02-18 1:59 ` H. Peter Anvin
2010-02-18 4:25 ` Zachary Amsden
2010-02-18 8:12 ` Andi Kleen
2010-02-18 8:24 ` Zachary Amsden
2010-02-18 9:29 ` Andi Kleen
2010-02-18 10:55 ` Ingo Molnar [this message]
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