Messages in this thread | | | Date | Sat, 1 Dec 2001 11:31:30 +0300 | From | Peter Zaitsev <> | Subject | Re[2]: your mail on mmap() to the kernel list |
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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
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