From: Peter Zaitsev <pz@spylog.ru>
To: theowl@freemail.c3.hu
Cc: theowl@freemail.hu, linux-kernel@vger.kernel.org
Subject: Re[2]: your mail on mmap() to the kernel list
Date: Sat, 1 Dec 2001 11:31:30 +0300 [thread overview]
Message-ID: <61437219298.20011201113130@spylog.ru> (raw)
In-Reply-To: <3C082244.8587.80EF082@localhost>
In-Reply-To: <3C082244.8587.80EF082@localhost>
Hello theowl,
Saturday, December 01, 2001, 2:20:20 AM, you wrote:
Well. Thank you. I've allready found this - in recent kernels it's
even regulated via proc fs.
The only question is why map anonymous is rather fast (i get
1000req/sec even then mapped 300.000 of blocks), therefore with
mapping a fd the perfomance drops to 20req/second at this number.
Any ideas why does this happen or any patches which increases the
speed exists ?
tfch> in include/linux/sched.h:
tfch> /* Maximum number of active map areas.. This is a random (large) number */
tfch> #define MAX_MAP_COUNT (65536)
tfch> this should probably be (TASK_SIZE / PAGE_SIZE) on 32 bit architectures
tfch> and something 'reasonably big' on 64 bit (too big of a value would
tfch> allow for a nice DoS against the kernel).
--
Best regards,
Peter mailto:pz@spylog.ru
next parent reply other threads:[~2001-12-01 8:28 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <3C082244.8587.80EF082@localhost>
2001-12-01 8:31 ` Peter Zaitsev [this message]
2001-12-01 9:37 ` your mail on mmap() to the kernel list Andrew Morton
2001-12-02 23:07 ` Re[2]: " Peter Zaitsev
2001-12-02 23:34 ` Andrew Morton
2001-12-03 10:10 ` Re[2]: " Peter Zaitsev
2001-12-04 14:18 ` Andrea Arcangeli
2001-12-04 14:15 ` Andrea Arcangeli
2001-12-04 15:36 ` Re[2]: " Peter Zaitsev
2001-12-04 16:42 ` Rik van Riel
2001-12-04 16:55 ` Andrea Arcangeli
2001-12-05 14:38 ` Re[2]: " Peter Zaitsev
2001-12-05 14:36 ` Re[3]: " Peter Zaitsev
2001-12-04 16:48 ` Andrea Arcangeli
2001-12-05 16:12 ` Re[2]: " Peter Zaitsev
2001-12-05 16:23 ` Andrea Arcangeli
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