Messages in this thread | | | Date | Sat, 3 Mar 2007 17:39:33 -0800 | From | Andrew Morton <> | Subject | Re: userspace pagecache management tool |
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On Sat, 3 Mar 2007 20:16:09 -0500 "Lee Revell" <rlrevell@joe-job.com> wrote:
> On 3/3/07, Andrew Morton <akpm@linux-foundation.org> wrote: > > The tool uses an LD_PRELOAD hack to intercept glibc's read(), pread(), > > write(), pwrite(), close() and dup2() functions. pagecache control is done > > via posix_fadvise() and sync_file_range(). > > > > How could this have any effect on the updatedb problem? updatedb does > not read() anything, it just open()s and stat()s every file on the > disk. >
err, good point. _one_ of those dang things which goes off when you've stayed up too late does a lot of pagecache IO, not sure which one. Maybe rpmq? But I'd expect that to be doing direct-io.
But yes, updatedb's pagecache usage will be mainly metadata, and this tool doesn't address metadata pagecache, although it could do so.
<does an updatedb on a modest system>
It instantiated 5MB of pagecache and 20MB of slab, took about one minute.
<runs all the other things in /etc/cron.daily>
rpm uses rather a lot of pagecache.
So yes, it looks like updatedb is a slab problem. - 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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