lkml.org 
[lkml]   [2006]   [Apr]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: Lockless page cache test results
    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/

    \
     
     \ /
      Last update: 2006-04-26 22:12    [W:4.248 / U:0.068 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site