Re: [patch v2] mm, compaction: avoid isolating pinned pages

2014-02-06 Thread David Rientjes
On Thu, 6 Feb 2014, Vlastimil Babka wrote: > > Page migration will fail for memory that is pinned in memory with, for > > example, get_user_pages(). In this case, it is unnecessary to take > > zone->lru_lock or isolating the page and passing it to page migration > > which will ultimately fail. >

Re: [patch v2] mm, compaction: avoid isolating pinned pages

2014-02-06 Thread Vlastimil Babka
On 5.2.2014 3:44, David Rientjes wrote: Page migration will fail for memory that is pinned in memory with, for example, get_user_pages(). In this case, it is unnecessary to take zone->lru_lock or isolating the page and passing it to page migration which will ultimately fail. This is a racy chec

Re: [patch v2] mm, compaction: avoid isolating pinned pages

2014-02-06 Thread Mel Gorman
On Wed, Feb 05, 2014 at 05:16:06PM -0800, Hugh Dickins wrote: > On Thu, 6 Feb 2014, Joonsoo Kim wrote: > > On Wed, Feb 05, 2014 at 12:56:40PM -0800, Hugh Dickins wrote: > > > On Tue, 4 Feb 2014, David Rientjes wrote: > > > > > > > Page migration will fail for memory that is pinned in memory with,

Re: [patch v2] mm, compaction: avoid isolating pinned pages

2014-02-05 Thread Hugh Dickins
On Thu, 6 Feb 2014, Joonsoo Kim wrote: > On Wed, Feb 05, 2014 at 12:56:40PM -0800, Hugh Dickins wrote: > > On Tue, 4 Feb 2014, David Rientjes wrote: > > > > > Page migration will fail for memory that is pinned in memory with, for > > > example, get_user_pages(). In this case, it is unnecessary to

Re: [patch v2] mm, compaction: avoid isolating pinned pages

2014-02-05 Thread Joonsoo Kim
On Wed, Feb 05, 2014 at 12:56:40PM -0800, Hugh Dickins wrote: > On Tue, 4 Feb 2014, David Rientjes wrote: > > > Page migration will fail for memory that is pinned in memory with, for > > example, get_user_pages(). In this case, it is unnecessary to take > > zone->lru_lock or isolating the page an

Re: [patch v2] mm, compaction: avoid isolating pinned pages

2014-02-05 Thread Hugh Dickins
On Tue, 4 Feb 2014, David Rientjes wrote: > Page migration will fail for memory that is pinned in memory with, for > example, get_user_pages(). In this case, it is unnecessary to take > zone->lru_lock or isolating the page and passing it to page migration > which will ultimately fail. > > This i

[patch v2] mm, compaction: avoid isolating pinned pages

2014-02-04 Thread David Rientjes
Page migration will fail for memory that is pinned in memory with, for example, get_user_pages(). In this case, it is unnecessary to take zone->lru_lock or isolating the page and passing it to page migration which will ultimately fail. This is a racy check, the page can still change from under us