Messages in this thread | | | Subject | Re: [PATCH 2/5] mm/debug_pagealloc: don't allocate page_ext if we don't use guard page | From | Vlastimil Babka <> | Date | Thu, 11 Aug 2016 11:53:18 +0200 |
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On 08/10/2016 08:16 AM, js1304@gmail.com wrote: > From: Joonsoo Kim <iamjoonsoo.kim@lge.com> > > What debug_pagealloc does is just mapping/unmapping page table. > Basically, it doesn't need additional memory space to memorize something. > But, with guard page feature, it requires additional memory to distinguish > if the page is for guard or not. Guard page is only used when > debug_guardpage_minorder is non-zero so this patch removes additional > memory allocation (page_ext) if debug_guardpage_minorder is zero. > > It saves memory if we just use debug_pagealloc and not guard page.
We could also save cycles with a static key for _debug_guardpage_enabled :)
But memory savings are likely more significant, so
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
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