From: Stephen Lord <lord@sgi.com>
To: Andrew Morton <akpm@zip.com.au>
Cc: Robert Love <rml@tech9.net>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] only irq-safe atomic ops
Date: Sat, 23 Feb 2002 14:01:07 -0600 [thread overview]
Message-ID: <3C77F503.1060005@sgi.com> (raw)
In-Reply-To: <3C773C02.93C7753E@zip.com.au>, <1014444810.1003.53.camel@phantasy> <3C773C02.93C7753E@zip.com.au> <1014449389.1003.149.camel@phantasy> <3C774AC8.5E0848A2@zip.com.au>
Andrew Morton wrote:
>Robert Love wrote:
>
>>...
>>
>>Question: if (from below) you are going to use atomic operations, why
>>make it per-CPU at all? Just have one counter and atomic_inc and
>>atomic_read it. You won't need a spin lock.
>>
>
>Oh that works fine. But then it's a global counter, so each time
>a CPU marks a page dirty, the counter needs to be pulled out of
>another CPU's cache. Which is not a thing I *need* to do.
>
>As I said, it's a micro-issue. But it's a requirement which
>may pop up elsewhere.
>
>
I can tell you that Irix has just such a global counter for the amount of
delayed allocate pages - and it gets to be a major point of cache contention
once you get to larger cpu counts. So avoiding that from the start would
be good.
Steve
next prev parent reply other threads:[~2002-02-23 20:00 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-02-23 6:13 [PATCH] only irq-safe atomic ops Robert Love
2002-02-23 6:51 ` Andrew Morton
2002-02-23 7:29 ` Robert Love
2002-02-23 7:54 ` Andrew Morton
2002-02-23 11:38 ` yodaiken
2002-02-23 18:20 ` Robert Love
2002-02-23 19:06 ` yodaiken
2002-02-23 21:57 ` Roman Zippel
2002-02-23 22:10 ` Andrew Morton
2002-02-23 22:23 ` yodaiken
2002-02-23 22:40 ` Andrew Morton
2002-02-23 22:48 ` yodaiken
2002-02-23 23:13 ` Robert Love
2002-02-23 23:45 ` Robert Love
2002-02-23 23:56 ` Andrew Morton
2002-02-24 1:05 ` yodaiken
2002-02-24 1:08 ` Robert Love
2002-02-23 22:00 ` John Levon
2002-02-23 22:43 ` yodaiken
2002-02-23 20:01 ` Stephen Lord [this message]
2002-02-23 20:27 ` Andrew Morton
2002-02-23 9:38 ` Russell King
[not found] <1014444810.1003.53.camel@phantasy.suse.lists.linux.kernel>
[not found] ` <3C773C02.93C7753E@zip.com.au.suse.lists.linux.kernel>
[not found] ` <1014449389.1003.149.camel@phantasy.suse.lists.linux.kernel>
[not found] ` <3C774AC8.5E0848A2@zip.com.au.suse.lists.linux.kernel>
[not found] ` <3C77F503.1060005@sgi.com.suse.lists.linux.kernel>
[not found] ` <3C77FB35.16844FE7@zip.com.au.suse.lists.linux.kernel>
2002-02-23 20:56 ` Andi Kleen
2002-02-23 21:06 ` Andrew Morton
2002-02-23 21:17 ` Stephen Lord
2002-02-23 21:42 ` Andrew Morton
2002-02-23 22:10 ` Stephen Lord
2002-02-23 22:34 ` Andrew Morton
2002-02-23 23:07 ` Mike Fedyk
2002-02-23 23:47 ` Andrew Morton
2002-02-25 13:02 ` Stephen Lord
2002-02-25 13:12 ` Jens Axboe
2002-02-25 13:18 ` Stephen Lord
2002-02-25 19:42 ` Andrew Morton
2002-02-25 19:45 ` Steve Lord
2002-02-25 20:05 ` Andrew Morton
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3C77F503.1060005@sgi.com \
--to=lord@sgi.com \
--cc=akpm@zip.com.au \
--cc=linux-kernel@vger.kernel.org \
--cc=rml@tech9.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.