Messages in this thread | | | Date | Wed, 31 Jul 2013 14:21:38 +0800 | Subject | Re: [PATCH 01/18] mm, hugetlb: protect reserved pages when softofflining requests the pages | From | Hillf Danton <> |
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On Wed, Jul 31, 2013 at 12:41 PM, Joonsoo Kim <iamjoonsoo.kim@lge.com> wrote: > On Wed, Jul 31, 2013 at 10:49:24AM +0800, Hillf Danton wrote: >> On Wed, Jul 31, 2013 at 10:27 AM, Joonsoo Kim <iamjoonsoo.kim@lge.com> wrote: >> > On Mon, Jul 29, 2013 at 03:24:46PM +0800, Hillf Danton wrote: >> >> On Mon, Jul 29, 2013 at 1:31 PM, Joonsoo Kim <iamjoonsoo.kim@lge.com> wrote: >> >> > alloc_huge_page_node() use dequeue_huge_page_node() without >> >> > any validation check, so it can steal reserved page unconditionally. >> >> >> >> Well, why is it illegal to use reserved page here? >> > >> > If we use reserved page here, other processes which are promised to use >> > enough hugepages cannot get enough hugepages and can die. This is >> > unexpected result to them. >> > >> But, how do you determine that a huge page is requested by a process >> that is not allowed to use reserved pages? > > Reserved page is just one for each address or file offset. If we need to > move this page, this means that it already use it's own reserved page, this > page is it. So we should not use other reserved page for moving this page. > Hm, how do you determine "this page" is not buddy?
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