Re: do_generic_mapping_read performance issue

2007-03-13 Thread Jan Kara
On Tue 13-03-07 14:43:47, Ashif Harji wrote: > > >>I would like to submit a patch to fix the performance problem. The > >>simplest solution is to remove the check. Even in the situation where an > >>application does not read in PAGE_SIZE multiples as described above, if > >>the page is accessed

Re: do_generic_mapping_read performance issue

2007-03-13 Thread Ashif Harji
I would like to submit a patch to fix the performance problem. The simplest solution is to remove the check. Even in the situation where an application does not read in PAGE_SIZE multiples as described above, if the page is accessed frequently it should remain in the cache. However, I am open

Re: do_generic_mapping_read performance issue

2007-03-12 Thread Jan Kara
On Mon 12-03-07 13:05:17, Ashif Harji wrote: > > On Mon, 12 Mar 2007, Jan Kara wrote: > > >On Mon 12-03-07 15:39:00, Nick Piggin wrote: > >>On Mon, Mar 12, 2007 at 03:20:12PM +0100, Jan Kara wrote: > >>> Hi, > >>> > Hi, I am encountering a performance problem, which I have tracked into > >>

Re: do_generic_mapping_read performance issue

2007-03-12 Thread Ashif Harji
On Mon, 12 Mar 2007, Jan Kara wrote: On Mon 12-03-07 15:39:00, Nick Piggin wrote: On Mon, Mar 12, 2007 at 03:20:12PM +0100, Jan Kara wrote: Hi, Hi, I am encountering a performance problem, which I have tracked into the Linux kernel. The problem occurs with my experimental web server that

Re: do_generic_mapping_read performance issue

2007-03-12 Thread Ashif Harji
The implication of this code is that for files of size less than or equal to a single page, the page associated with such a file is likely to get evicted from the cache regardless of how frequently it is accessed. The reason is that after the first access, prev_index is always zero and index ca

Re: do_generic_mapping_read performance issue

2007-03-12 Thread Jan Kara
On Mon 12-03-07 15:39:00, Nick Piggin wrote: > On Mon, Mar 12, 2007 at 03:20:12PM +0100, Jan Kara wrote: > > Hi, > > > > > Hi, I am encountering a performance problem, which I have tracked into > > > the > > > Linux kernel. The problem occurs with my experimental web server that > > > uses >

Re: do_generic_mapping_read performance issue

2007-03-12 Thread Nick Piggin
On Mon, Mar 12, 2007 at 03:20:12PM +0100, Jan Kara wrote: > Hi, > > > Hi, I am encountering a performance problem, which I have tracked into the > > Linux kernel. The problem occurs with my experimental web server that uses > > sendfile to repeatedly transmit files. The files are based on the

Re: do_generic_mapping_read performance issue

2007-03-12 Thread Jan Kara
Hi, > Hi, I am encountering a performance problem, which I have tracked into the > Linux kernel. The problem occurs with my experimental web server that uses > sendfile to repeatedly transmit files. The files are based on the static > portion of the SPECweb99 fileset and range in size to mod