Messages in this thread | | | Subject | Re: [PATCH v4 1/2] mm: introduce page reference manipulation functions | From | Vlastimil Babka <> | Date | Wed, 2 Mar 2016 17:44:16 +0100 |
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On 02/26/2016 01:58 AM, js1304@gmail.com wrote: > From: Joonsoo Kim <iamjoonsoo.kim@lge.com> > > Success of CMA allocation largely depends on success of migration > and key factor of it is page reference count. Until now, page reference > is manipulated by direct calling atomic functions so we cannot follow up > who and where manipulate it. Then, it is hard to find actual reason > of CMA allocation failure. CMA allocation should be guaranteed to succeed > so finding offending place is really important. > > In this patch, call sites where page reference is manipulated are converted > to introduced wrapper function. This is preparation step to add tracepoint > to each page reference manipulation function. With this facility, we can > easily find reason of CMA allocation failure. There is no functional change > in this patch. > > In addition, this patch also converts reference read sites. It will help > a second step that renames page._count to something else and prevents later > attempt to direct access to it (Suggested by Andrew). > > Acked-by: Michal Nazarewicz <mina86@mina86.com> > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Even without Patch 2/2 this is a nice improvement. Acked-by: Vlastimil Babka <vbabka@suse.cz>
Although somebody might be confused by page_ref_count() vs page_count(). Oh well.
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