Messages in this thread | | | Date | Sat, 4 Aug 2007 09:51:43 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH 00/23] per device dirty throttling -v8 |
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On Sat, 4 Aug 2007 18:37:33 +0200 Ingo Molnar <mingo@elte.hu> wrote:
> > * Linus Torvalds <torvalds@linux-foundation.org> wrote: > > > > hm, it turns out that it's due to vim doing an occasional fsync not > > > only on writeout, but during normal use too. "set nofsync" in the > > > .vimrc solves this problem. > > > > Yes, that's independent. The fact is, ext3 *sucks* at fsync. I hate > > hate hate it. It's totally unusable, imnsho. > > yeah, it's really ugly. But otherwise i've got no real complaint about > ext3 - with the obligatory qualification that "noatime,nodiratime" in > /etc/fstab is a must. This speeds up things very visibly - especially > when lots of files are accessed. It's kind of weird that every Linux > desktop and server is hurt by a noticeable IO performance slowdown due > to the constant atime updates,
Not just more IO: it will cause great gobs of blockdev pagecache to remain in memory, too.
> while there's just two real users of it: > tmpwatch [which can be configured to use ctime so it's not a big issue] > and some backup tools. (Ok, and mail-notify too i guess.) Out of tens of > thousands of applications. So for most file workloads we give Windows a > 20%-30% performance edge, for almost nothing. (for RAM-starved kernel > builds the performance difference between atime and noatime+nodiratime > setups is more on the order of 40%) > > Ingo - 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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