[RFC 2/2] cma: support MIGRATE_DISCARD

2012-08-14 Thread Minchan Kim
This patch introudes MIGRATE_DISCARD mode in migration. It drop clean cache pages instead of migration so that migration latency could be reduced. Of course, it could evict code pages but latency of big contiguous memory is more important than some background application's slow down in mobile embed

Re: [RFC 2/2] cma: support MIGRATE_DISCARD

2012-08-14 Thread Michal Nazarewicz
Minchan Kim writes: > This patch introudes MIGRATE_DISCARD mode in migration. > It drop clean cache pages instead of migration so that > migration latency could be reduced. Of course, it could > evict code pages but latency of big contiguous memory > is more important than some background applicat

Re: [RFC 2/2] cma: support MIGRATE_DISCARD

2012-08-15 Thread Rik van Riel
On 08/14/2012 04:57 AM, Minchan Kim wrote: This patch introudes MIGRATE_DISCARD mode in migration. It drop clean cache pages instead of migration so that migration latency could be reduced. Of course, it could evict code pages but latency of big contiguous memory is more important than some backg

Re: [RFC 2/2] cma: support MIGRATE_DISCARD

2012-08-15 Thread Minchan Kim
Hi Michal, On Tue, Aug 14, 2012 at 04:19:55PM +0200, Michal Nazarewicz wrote: > Minchan Kim writes: > > This patch introudes MIGRATE_DISCARD mode in migration. > > It drop clean cache pages instead of migration so that > > migration latency could be reduced. Of course, it could > > evict code pag

Re: [RFC 2/2] cma: support MIGRATE_DISCARD

2012-08-15 Thread Minchan Kim
Hi Rik, On Wed, Aug 15, 2012 at 02:58:01PM -0400, Rik van Riel wrote: > On 08/14/2012 04:57 AM, Minchan Kim wrote: > >This patch introudes MIGRATE_DISCARD mode in migration. > >It drop clean cache pages instead of migration so that > >migration latency could be reduced. Of course, it could > >evic

Re: [RFC 2/2] cma: support MIGRATE_DISCARD

2012-08-15 Thread Minchan Kim
On Thu, Aug 16, 2012 at 08:33:23AM +0900, Minchan Kim wrote: > Hi Rik, > > On Wed, Aug 15, 2012 at 02:58:01PM -0400, Rik van Riel wrote: > > On 08/14/2012 04:57 AM, Minchan Kim wrote: > > >This patch introudes MIGRATE_DISCARD mode in migration. > > >It drop clean cache pages instead of migration s

Re: [RFC 2/2] cma: support MIGRATE_DISCARD

2012-08-16 Thread Michal Nazarewicz
> On Tue, Aug 14, 2012 at 04:19:55PM +0200, Michal Nazarewicz wrote: >> Since CMA is the only user of MIGRATE_DISCARD it may be worth it to >> guard it inside an #ifdef, eg: Minchan Kim writes: > In summary, I want to open it for potential usecases in future if anyone > doesn't oppose strongly.