Re: [PATCH] Significant performace improvements on reiserfs systems

Andrea Arcangeli
2001-09-20T18:47:56Z

On Thu, Sep 20, 2001 at 01:19:53PM -0400, Chris Mason wrote:
>
>
> On Thursday, September 20, 2001 07:08:25 PM +0200 Dieter Nützel
> <Dieter.Nuetzel@hamburg.de> wrote:
>
>
> > Please have a look at Robert Love's Linux kernel preemption patches and
> > the conversation about my reported latency results.
> >
>
> Andrew Morton has patches that significantly improve the reiserfs latency,
> looks like the last one he sent me was 2.4.7-pre9. He and I did a bunch of
> work to make sure they introduce schedules only when it was safe.
>
> Andrew, are these still maintained or should I pull out the reiserfs bits?

May not help latency but I suspect this could help reiserfs, it should
basically be a noop for ext2.

--- 2.4.10pre12aa2/fs/buffer.c.~1~ Thu Sep 20 20:14:19 2001
+++ 2.4.10pre12aa2/fs/buffer.c Thu Sep 20 20:45:58 2001
@@ -2506,7 +2506,7 @@
spin_unlock(&free_list[isize].lock);

page->buffers = bh;
- page->flags &= ~(1 << PG_referenced);
+ page->flags |= 1 << PG_referenced;
lru_cache_add(page);
UnlockPage(page);
atomic_inc(&buffermem_pages);

You may want to give it a spin.

Andrea