Messages in this thread | | | Date | Wed, 26 Apr 2006 13:12:00 -0700 | From | Andrew Morton <> | Subject | Re: Lockless page cache test results |
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Jens Axboe <axboe@suse.de> wrote: > > With a 16-page gang lookup in splice, the top profile for the 4-client > case (which is now at 4GiB/sec instead of 3) are: > > samples % symbol name > 30396 36.7217 __do_page_cache_readahead > 25843 31.2212 find_get_pages_contig > 9699 11.7174 default_idle
__do_page_cache_readahead() should use gang lookup. We never got around to that, mainly because nothing really demonstrated a need.
It's a problem that __do_page_cache_readahead() is being called at all - with everything in pagecache we should be auto-turning-off readahead. This happens because splice is calling the low-level do_pagecache_readahead(). If you convert it to use page_cache_readahead(), that will all vanish if readahead is working right. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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