Messages in this thread | | | Date | Fri, 23 Sep 2016 10:07:10 +0200 | From | Michal Hocko <> | Subject | Re: [RFC] scripts: Include postprocessing script for memory allocation tracing |
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On Thu 22-09-16 11:30:36, Janani Ravichandran wrote: > > > On Sep 19, 2016, at 5:42 AM, Michal Hocko <mhocko@kernel.org> wrote: > > > > On Tue 13-09-16 14:04:49, Janani Ravichandran wrote: > >> > >>> On Sep 12, 2016, at 8:16 AM, Michal Hocko <mhocko@kernel.org> wrote: > >> > >> I’m using the function graph tracer to see how long __alloc_pages_nodemask() > >> took. > > > > How can you map the function graph tracer to a specif context? Let's say > > I would like to know why a particular allocation took so long. Would > > that be possible? > > Maybe not. If the latencies are due to direct reclaim or memory compaction, you > get some information from the tracepoints (like mm_vmscan_direct_reclaim_begin, > mm_compaction_begin, etc). But otherwise, you don’t get any context information. > Function graph only gives the time spent in alloc_pages_nodemask() in that case.
Then I really think that we need a starting trace point. I think that having the full context information is really helpful in order to understand latencies induced by allocations. -- Michal Hocko SUSE Labs
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