From: Hiro Yoshioka <lkml.hyoshiok@gmail.com>
To: Andi Kleen <ak@suse.de>
Cc: Arjan van de Ven <arjan@infradead.org>,
taka@valinux.co.jp, linux-kernel@vger.kernel.org,
Hiro Yoshioka <hyoshiok@miraclelinux.com>
Subject: Re: [RFC] [PATCH] cache pollution aware __copy_from_user_ll()
Date: Thu, 18 Aug 2005 20:06:39 +0900 [thread overview]
Message-ID: <98df96d305081804061ea70686@mail.gmail.com> (raw)
In-Reply-To: <p73oe7y10qw.fsf@verdi.suse.de>
On 16 Aug 2005 15:15:35 +0200, Andi Kleen <ak@suse.de> wrote:
> However it disables preemption, which especially for bigger
> copies will probably make the low latency people unhappy.
In the copy loop,
+#ifdef CONFIG_PREEMPT
+ if ( (i%64)==0 ) {
+ MMX_RESTORE;
+ MMX_SAVE;
+ };
+#endif
It costs several hundred clocks (wow) every 4KB copy.
It kills throughput but it makes the low latency people smile.
So I make two APIs.
__copy_user_zeroing_nocache()
__copy_user_zeroing_inatomic_nocache()
The former is a low latency version and the other is a throughput version.
What do you think?
Regards,
Hiro
--
Hiro Yoshioka
mailto:hyoshiok at miraclelinux.com
next prev parent reply other threads:[~2005-08-18 11:06 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20050816.131729.15816429.taka@valinux.co.jp.suse.lists.linux.kernel>
[not found] ` <20050816.135425.719901536.hyoshiok@miraclelinux.com.suse.lists.linux.kernel>
[not found] ` <1124171015.3215.0.camel@laptopd505.fenrus.org.suse.lists.linux.kernel>
[not found] ` <20050816.191617.1025215458.hyoshiok@miraclelinux.com.suse.lists.linux.kernel>
[not found] ` <1124187950.3215.31.camel@laptopd505.fenrus.org.suse.lists.linux.kernel>
2005-08-16 13:15 ` [RFC] [PATCH] cache pollution aware __copy_from_user_ll() Andi Kleen
2005-08-18 11:06 ` Hiro Yoshioka [this message]
2005-08-18 11:11 ` Hiro Yoshioka
2005-08-18 23:29 ` Hiro Yoshioka
2005-08-22 1:24 ` Hiro Yoshioka
2005-08-22 13:07 ` Andi Kleen
2005-08-22 2:43 ` Hiro Yoshioka
2005-08-22 23:12 ` Hiro Yoshioka
2005-08-24 14:11 ` Hiro Yoshioka
2005-08-24 14:21 ` Arjan van de Ven
2005-08-24 16:22 ` Hirokazu Takahashi
2005-08-25 4:53 ` Hiro Yoshioka
[not found] <20050818.201138.607962419.hyoshiok@miraclelinux.com.suse.lists.linux.kernel>
[not found] ` <98df96d30508181629d85edb5@mail.gmail.com.suse.lists.linux.kernel>
[not found] ` <20050823.081246.846946371.hyoshiok@miraclelinux.com.suse.lists.linux.kernel>
[not found] ` <20050824.231156.278740508.hyoshiok@miraclelinux.com.suse.lists.linux.kernel>
2005-08-24 16:18 ` Andi Kleen
2005-08-25 4:54 ` Hiro Yoshioka
2005-09-01 9:07 ` Hiro Yoshioka
2005-09-01 9:36 ` Andi Kleen
2005-09-02 1:43 ` Hiro Yoshioka
2005-09-02 2:06 ` Andi Kleen
2005-09-02 2:08 ` Andrew Morton
2005-09-02 2:17 ` Andi Kleen
2005-09-02 2:28 ` Andrew Morton
2005-09-02 3:41 ` Hiro Yoshioka
2005-09-02 4:29 ` Andrew Morton
2005-09-02 4:37 ` Hiro Yoshioka
2005-09-03 11:59 ` Hiro Yoshioka
2005-08-17 15:19 Chuck Ebbert
2005-08-18 9:45 ` Hiro Yoshioka
-- strict thread matches above, loose matches on Subject: below --
2005-08-16 18:09 Chuck Ebbert
2005-08-16 23:21 ` Hiro Yoshioka
2005-08-17 4:50 ` Hiro Yoshioka
[not found] <20050815121555.29159.qmail@science.horizon.com.suse.lists.linux.kernel>
[not found] ` <1124108702.3228.33.camel@laptopd505.fenrus.org.suse.lists.linux.kernel>
2005-08-15 15:02 ` Andi Kleen
2005-08-15 15:09 ` Arjan van de Ven
2005-08-15 15:13 ` Andi Kleen
2005-08-15 12:15 linux
2005-08-15 12:25 ` Arjan van de Ven
2005-08-14 21:24 Ian Kumlien
2005-08-15 7:21 ` Arjan van de Ven
2005-08-15 14:49 ` Ian Kumlien
2005-08-14 9:16 Hiro Yoshioka
2005-08-14 9:41 ` Arjan van de Ven
2005-08-14 10:22 ` Hiro Yoshioka
2005-08-14 10:35 ` Arjan van de Ven
2005-08-14 10:45 ` Christoph Hellwig
2005-08-15 6:43 ` Hiro Yoshioka
2005-08-15 7:16 ` Arjan van de Ven
2005-08-15 8:44 ` Hiro Yoshioka
2005-08-15 8:53 ` Arjan van de Ven
2005-08-15 23:33 ` Hiro Yoshioka
2005-08-16 3:30 ` Hiro Yoshioka
2005-08-16 4:17 ` Hirokazu Takahashi
2005-08-16 4:54 ` Hiro Yoshioka
2005-08-16 5:43 ` Arjan van de Ven
2005-08-16 10:16 ` Hiro Yoshioka
2005-08-16 10:19 ` Hirokazu Takahashi
2005-08-16 10:25 ` Arjan van de Ven
2005-08-16 10:24 ` Hirokazu Takahashi
2005-08-16 5:44 ` Arjan van de Ven
2005-08-16 5:49 ` Arjan van de Ven
[not found] ` <20050817.110503.97359275.taka@valinux.co.jp>
2005-08-17 5:10 ` Hiro Yoshioka
2005-08-17 14:30 ` Akira Tsukamoto
2005-08-17 15:27 ` Akira Tsukamoto
2005-08-18 17:53 ` Lee Revell
2005-08-18 2:37 ` Akira Tsukamoto
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