Re: [PATCH] kswapd should only wait on IO if there is IO

2007-09-27 Thread Rik van Riel
On Thu, 27 Sep 2007 15:59:07 -0700 Andrew Morton <[EMAIL PROTECTED]> wrote: > And lost the changelog ;) Good point. The current kswapd (and try_to_free_pages) code has an oddity where the code will wait on IO, even if there is no IO in flight. This problem is notable especially when the system

Re: [PATCH] kswapd should only wait on IO if there is IO

2007-09-27 Thread Andrew Morton
On Thu, 27 Sep 2007 18:50:27 -0400 Rik van Riel <[EMAIL PROTECTED]> wrote: > On Thu, 27 Sep 2007 15:21:21 -0700 > Andrew Morton <[EMAIL PROTECTED]> wrote: > > > > Nope, sc.nr_io_pages will also be incremented when the code runs into > > > pages that are already PageWriteback. > > > > yup, I didn

Re: [PATCH] kswapd should only wait on IO if there is IO

2007-09-27 Thread Rik van Riel
On Thu, 27 Sep 2007 15:21:21 -0700 Andrew Morton <[EMAIL PROTECTED]> wrote: > > Nope, sc.nr_io_pages will also be incremented when the code runs into > > pages that are already PageWriteback. > > yup, I didn't think of that. Hopefully someone else will be in there > working on that zone too. If

Re: [PATCH] kswapd should only wait on IO if there is IO

2007-09-27 Thread Andrew Morton
On Thu, 27 Sep 2007 18:13:25 -0400 Rik van Riel <[EMAIL PROTECTED]> wrote: > On Thu, 27 Sep 2007 14:47:02 -0700 > Andrew Morton <[EMAIL PROTECTED]> wrote: > > > On Thu, 27 Sep 2007 17:08:16 -0400 > > Rik van Riel <[EMAIL PROTECTED]> wrote: > > > > > The current kswapd (and try_to_free_pages) cod

Re: [PATCH] kswapd should only wait on IO if there is IO

2007-09-27 Thread Rik van Riel
On Thu, 27 Sep 2007 14:47:02 -0700 Andrew Morton <[EMAIL PROTECTED]> wrote: > On Thu, 27 Sep 2007 17:08:16 -0400 > Rik van Riel <[EMAIL PROTECTED]> wrote: > > > The current kswapd (and try_to_free_pages) code has an oddity where the > > code will wait on IO, even if there is no IO in flight. Thi

Re: [PATCH] kswapd should only wait on IO if there is IO

2007-09-27 Thread Andrew Morton
On Thu, 27 Sep 2007 17:08:16 -0400 Rik van Riel <[EMAIL PROTECTED]> wrote: > The current kswapd (and try_to_free_pages) code has an oddity where the > code will wait on IO, even if there is no IO in flight. This problem is > notable especially when the system scans through many unfreeable pages,

[PATCH] kswapd should only wait on IO if there is IO

2007-09-27 Thread Rik van Riel
The current kswapd (and try_to_free_pages) code has an oddity where the code will wait on IO, even if there is no IO in flight. This problem is notable especially when the system scans through many unfreeable pages, causing unnecessary stalls in the VM. Signed-off-by: Rik van Riel <[EMAIL PROTECT