Messages in this thread | | | Date | Thu, 29 Jul 1999 00:45:49 +0100 | From | Steve Dodd <> | Subject | Re: (disk/cpu) kernel performance problem |
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On Wed, Jul 28, 1999 at 04:12:59PM -0700, Gerald Aigner wrote:
> In addition to that and maybe more promising is the possibility to > map the page cache straight into the users address space and use copy on > write if the user modifies the read buffer. (this of course works only > if the readbuffer is aligned on a 4K boundary and the whole page is read > in)
Ewww.. That basically *is* an mmap(), though, isn't it..
> I also profiled the mmapped code and found no such bottlenecks. The CPU > was mostly idle. Unfortunately a lock in the kernel serializes a > significant part of the mmap operation therefore leading to a slower > overall execution time (see my previous postings).
Well, it's been mentioned a number of times that one of the big goals for 2.3/2.4 is to improve SMP performance by finer locking granularity, so it wouldn't surprise me if someone's thinking about this issue already. Maybe sct has already done it :-)
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