From: Andi Kleen <andi@firstfloor.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arjan van de Ven <arjan@infradead.org>,
Ingo Molnar <mingo@elte.hu>,
Nick Piggin <nickpiggin@yahoo.com.au>,
Salman Qazi <sqazi@google.com>,
davem@davemloft.net, linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [patch] x86, mm: pass in 'total' to __copy_from_user_*nocache()
Date: Sat, 28 Feb 2009 19:05:22 +0100 [thread overview]
Message-ID: <8763iu309p.fsf@basil.nowhere.org> (raw)
In-Reply-To: <alpine.LFD.2.00.0902280935010.3111@localhost.localdomain> (Linus Torvalds's message of "Sat, 28 Feb 2009 09:42:18 -0800 (PST)")
Linus Torvalds <torvalds@linux-foundation.org> writes:
> That's almost unacceptable in the long run. With a 8MB L3 cache - and a
> compile sequence, do we really want to go out to memory to write the .S
> file, and then have the assembler go out to memory to read it back? For
One possible way would be to make the threshold dependent on the LLC
cache size, so that let's say an Atom still prefers to not pollute
its caches. But I agree with you that it's probably better to
just drop the nocache copies completely.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2009-02-28 18:07 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-24 2:03 Performance regression in write() syscall Salman Qazi
2009-02-24 4:10 ` Nick Piggin
2009-02-24 4:28 ` Linus Torvalds
2009-02-24 9:02 ` Nick Piggin
2009-02-24 15:52 ` Linus Torvalds
2009-02-24 16:24 ` Andi Kleen
2009-02-24 16:51 ` Ingo Molnar
2009-02-25 3:23 ` Nick Piggin
2009-02-25 7:25 ` [patch] x86, mm: pass in 'total' to __copy_from_user_*nocache() Ingo Molnar
2009-02-25 8:09 ` Nick Piggin
2009-02-25 8:29 ` Ingo Molnar
2009-02-25 8:59 ` Nick Piggin
2009-02-25 12:01 ` Ingo Molnar
2009-02-25 16:04 ` Linus Torvalds
2009-02-25 16:29 ` Ingo Molnar
2009-02-27 12:05 ` Nick Piggin
2009-02-28 8:29 ` Ingo Molnar
2009-02-28 11:49 ` Nick Piggin
2009-02-28 12:58 ` Ingo Molnar
2009-02-28 17:16 ` Linus Torvalds
2009-02-28 17:24 ` Arjan van de Ven
2009-02-28 17:42 ` Linus Torvalds
2009-02-28 17:53 ` Arjan van de Ven
2009-02-28 18:05 ` Andi Kleen [this message]
2009-02-28 18:27 ` Ingo Molnar
2009-02-28 18:39 ` Arjan van de Ven
2009-03-02 10:39 ` [PATCH] x86, mm: dont use non-temporal stores in pagecache accesses Ingo Molnar
2009-02-28 18:52 ` [patch] x86, mm: pass in 'total' to __copy_from_user_*nocache() Linus Torvalds
2009-03-01 14:19 ` Nick Piggin
2009-03-01 0:06 ` David Miller
2009-03-01 0:40 ` Andi Kleen
2009-03-01 0:28 ` H. Peter Anvin
2009-03-01 0:38 ` Arjan van de Ven
2009-03-01 1:48 ` Andi Kleen
2009-03-01 1:38 ` Arjan van de Ven
2009-03-01 1:40 ` H. Peter Anvin
2009-03-01 14:06 ` Nick Piggin
2009-03-02 4:46 ` H. Peter Anvin
2009-03-02 6:18 ` Nick Piggin
2009-03-02 21:16 ` Linus Torvalds
2009-03-02 21:25 ` Ingo Molnar
2009-03-03 4:30 ` Nick Piggin
2009-03-03 4:20 ` Nick Piggin
2009-03-03 9:02 ` Ingo Molnar
2009-03-04 3:37 ` Nick Piggin
2009-03-01 2:07 ` Andi Kleen
2009-02-24 5:43 ` Performance regression in write() syscall Salman Qazi
2009-02-24 10:09 ` Andi Kleen
2009-02-24 16:13 ` Ingo Molnar
2009-02-24 16:51 ` Andi Kleen
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