Re: fs/stat: Reduce memory requirements for stat_open

2014-07-08 Thread Stefan Bader
On 08.07.2014 15:09, Peter Zijlstra wrote: > On Thu, Jun 12, 2014 at 03:00:17PM +0200, Stefan Bader wrote: >> When reading from /proc/stat we allocate a large buffer to maximise >> the chances of the results being from a single run and thus internally >> consistent. This currently is sized at 128

Re: fs/stat: Reduce memory requirements for stat_open

2014-07-08 Thread Peter Zijlstra
On Thu, Jun 12, 2014 at 03:00:17PM +0200, Stefan Bader wrote: > When reading from /proc/stat we allocate a large buffer to maximise > the chances of the results being from a single run and thus internally > consistent. This currently is sized at 128 * num_possible_cpus() which, > in the face of ke

Re: fs/stat: Reduce memory requirements for stat_open

2014-06-25 Thread Andrew Morton
On Wed, 25 Jun 2014 15:52:30 -0700 (PDT) David Rientjes wrote: > On Wed, 25 Jun 2014, Stefan Bader wrote: > > > Heiko and I both had the same issue. Since some x86 hardware also reaches a > > lot > > of CPUs (hyperthreads included), we bumped the possible number of CPUs to > > 256 at > > leas

Re: fs/stat: Reduce memory requirements for stat_open

2014-06-25 Thread David Rientjes
On Wed, 25 Jun 2014, Stefan Bader wrote: > Heiko and I both had the same issue. Since some x86 hardware also reaches a > lot > of CPUs (hyperthreads included), we bumped the possible number of CPUs to 256 > at > least for the 64bit kernel. And that resulted in failed accesses to /proc/stat > whe

Re: fs/stat: Reduce memory requirements for stat_open

2014-06-25 Thread Stefan Bader
On 25.06.2014 01:44, David Rientjes wrote: > On Thu, 12 Jun 2014, Stefan Bader wrote: > >> doh, so you guys have been hit by that before. And I have missed the fact >> that >> single_open is special. Which makes the change for the upper limit do the >> wrong >> thing. While long-term it sounds l

Re: fs/stat: Reduce memory requirements for stat_open

2014-06-24 Thread David Rientjes
On Thu, 12 Jun 2014, Stefan Bader wrote: > doh, so you guys have been hit by that before. And I have missed the fact that > single_open is special. Which makes the change for the upper limit do the > wrong > thing. While long-term it sounds like changing it to vmalloc or iterative > reads > soun

Re: fs/stat: Reduce memory requirements for stat_open

2014-06-12 Thread Stefan Bader
On 12.06.2014 15:41, Heiko Carstens wrote: > On Thu, Jun 12, 2014 at 03:00:17PM +0200, Stefan Bader wrote: >> When reading from /proc/stat we allocate a large buffer to maximise >> the chances of the results being from a single run and thus internally >> consistent. This currently is sized at 128

Re: fs/stat: Reduce memory requirements for stat_open

2014-06-12 Thread Heiko Carstens
On Thu, Jun 12, 2014 at 03:00:17PM +0200, Stefan Bader wrote: > When reading from /proc/stat we allocate a large buffer to maximise > the chances of the results being from a single run and thus internally > consistent. This currently is sized at 128 * num_possible_cpus() which, > in the face of ke

fs/stat: Reduce memory requirements for stat_open

2014-06-12 Thread Stefan Bader
sense generally? It seemed to stop top complaining wildly for the reporter at least. -Stefan --- >From a329ad61fbd26990b294f3b35a31ec80ffab35bb Mon Sep 17 00:00:00 2001 From: Stefan Bader Date: Wed, 14 May 2014 12:58:37 +0200 Subject: [PATCH] fs/stat: Reduce memory requirements for stat_open W