Re: [PATCH 1/2] mm: page_alloc.c: Add tracepoints for slowpath
From: Michal Hocko <mhocko@kernel.org>
Date: 2016-07-27 18:44:49
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On Wed 27-07-16 14:16:22, Rik van Riel wrote:
On Wed, 2016-07-27 at 18:33 +0200, Michal Hocko wrote:quoted
On Wed 27-07-16 10:47:59, Janani Ravichandran wrote:quoted
Add tracepoints to the slowpath code to gather some information. The tracepoints can also be used to find out how much time was spent in the slowpath.I do not think this is a right thing to measure. __alloc_pages_slowpath is more a code organization thing. The fast path might perform an expensive operations like zone reclaim (if node_reclaim_mode > 0) so these trace point would miss it.It doesn't look like it does. The fast path either returns an allocated page to the caller, or calls into the slow path.
I must be missing something here but what prevents __alloc_pages_nodemask->get_page_from_freelist from doing zone_reclaim? -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>