Re: [ck] Re: [announce] [patch] Voluntary Kernel Preemption Patch

[Con Kolivas]

Ingo Molnar wrote:
> * Con Kolivas <kernel@xxxxxxxxxxx> wrote:
>
>
> > Ooops forgot to mention this was running reiserFS 3.6 on software
> > raid0 2x IDE with cfq elevator.
>
>
> ok, reiserfs (and all journalling fs's) definitely need a look - as you
> can see from the ext3 mods in the patch. Any chance you could try ext3
> based tests? Those are the closest to my setups.

Ok I've done one better than that ;) I had wli help make some 
instrumentation for me to help find the remaining non preemptible kernel 
portions and set the cutoff to 2ms. Here is what I found:

7ms non-preemptible critical section violated 2 ms preempt threshold 
starting at reiserfs_sync_fs+0x2d/0xc2 and ending at reiser
fs_lookup+0xe2/0x221

9ms non-preemptible critical section violated 2 ms preempt threshold 
starting at reiserfs_dirty_inode+0x37/0x10e and ending at r
eiserfs_dirty_inode+0xb0/0x10e


These seem to be the two offenders. Hope this helps.

Con

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