[lkml]   [2005]   [Mar]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [patch] optimization: defer bio_vec deallocation
On Mon, Mar 28 2005, Chen, Kenneth W wrote:
> On Mon, Mar 28, 2005 at 06:38:23PM -0800, Chen, Kenneth W wrote:
> > We have measured that the following patch give measurable performance gain
> > for industry standard db benchmark. Comments?
> Dave Jones wrote on Monday, March 28, 2005 7:00 PM
> > If you can't publish results from that certain benchmark due its stupid
> > restrictions, could you also try running an alternative benchmark that
> > you can show results from ?
> >
> > These nebulous claims of 'measurable gains' could mean anything.
> > I'm assuming you see a substantial increase in throughput, but
> > how much is it worth in exchange for complicating the code?
> Are you asking for micro-benchmark result? I had a tough time last time
> around when I presented micro-benchmark result on LKML. I got kicked in
> the butt for lack of evidence with performance data running real bench on
> real hardware.
> I guess either way, I'm bruised one way or the other.

Just _some_ results would be nice, Dave is right in that 'measurable
gains' doesn't really say anything at all. Personally I would like to
see a profile diff, for instance. And at least something like 'we get 1%
gain bla bla'.

Now, about the patch. I cannot convince myself that it is not deadlock
prone, if someone waits for a bvec to be freed. Will slab reclaim always
prune the bio slab and push the bvecs back into the mempool, or can
there be cases where this doesn't happen?

Jens Axboe

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-04-06 13:31    [W:0.056 / U:0.908 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site