From: Linus Torvalds <torvalds@linux-foundation.org>
To: David Miller <davem@davemloft.net>
Cc: linux-arch@vger.kernel.org, mingo@elte.hu,
benh@kernel.crashing.org, rmk@arm.linux.org.uk
Subject: Re: Software prefetching considered harmful
Date: Thu, 19 May 2011 12:38:40 -0700 [thread overview]
Message-ID: <BANLkTi=0N55+mQjE1gq8DHdoQ0GU0A7kLw@mail.gmail.com> (raw)
In-Reply-To: <20110519.153259.1670240855485459381.davem@davemloft.net>
On Thu, May 19, 2011 at 12:32 PM, David Miller <davem@davemloft.net> wrote:
>
> It's been my experience that prefetch hurts more than it ever helps
> for these list traversal functions.
>
> In fact I had been looking at some assembler output for files in the
> networking and noticed how all of these list prefetch turds just take
> up I-cache space.
>
> Please kill them off, you have my utmost support :-)
Hmm. Networking tends to use both hlist and regular lists. Does it go
for both for you, or is one or the other more of an issue?
Lius
next prev parent reply other threads:[~2011-05-19 19:39 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-19 17:12 Software prefetching considered harmful Linus Torvalds
2011-05-19 19:05 ` Linus Torvalds
2011-05-19 19:28 ` Ingo Molnar
2011-05-21 3:37 ` Michael Cree
2011-05-21 4:18 ` Benjamin Herrenschmidt
2011-05-21 10:42 ` Ingo Molnar
2011-05-19 19:32 ` David Miller
2011-05-19 19:38 ` Linus Torvalds [this message]
2011-05-19 19:47 ` David Miller
2011-05-19 23:34 ` Ingo Molnar
2011-05-20 16:01 ` Catalin Marinas
2011-05-20 1:42 ` Benjamin Herrenschmidt
2011-05-20 8:34 ` Ingo Molnar
2011-05-20 9:13 ` Benjamin Herrenschmidt
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