Re: [PATCH v2 1/2] free_pcppages_bulk: do not hold lock when picking pages to free

2018-02-22 Thread Aaron Lu
On Thu, Feb 15, 2018 at 04:46:44AM -0800, Matthew Wilcox wrote: > On Thu, Jan 25, 2018 at 03:21:44PM +0800, Aaron Lu wrote: > > When freeing a batch of pages from Per-CPU-Pages(PCP) back to buddy, > > the zone->lock is held and then pages are chosen from PCP's migratetype > > list. While there is a

Re: [PATCH v2 1/2] free_pcppages_bulk: do not hold lock when picking pages to free

2018-02-22 Thread Aaron Lu
On Thu, Feb 15, 2018 at 12:06:08PM +, Mel Gorman wrote: > On Thu, Jan 25, 2018 at 03:21:44PM +0800, Aaron Lu wrote: > > When freeing a batch of pages from Per-CPU-Pages(PCP) back to buddy, > > the zone->lock is held and then pages are chosen from PCP's migratetype > > list. While there is actua

Re: [PATCH v2 1/2] free_pcppages_bulk: do not hold lock when picking pages to free

2018-02-15 Thread Mel Gorman
On Thu, Feb 15, 2018 at 04:46:44AM -0800, Matthew Wilcox wrote: > On Thu, Jan 25, 2018 at 03:21:44PM +0800, Aaron Lu wrote: > > When freeing a batch of pages from Per-CPU-Pages(PCP) back to buddy, > > the zone->lock is held and then pages are chosen from PCP's migratetype > > list. While there is a

Re: [PATCH v2 1/2] free_pcppages_bulk: do not hold lock when picking pages to free

2018-02-15 Thread Matthew Wilcox
On Thu, Jan 25, 2018 at 03:21:44PM +0800, Aaron Lu wrote: > When freeing a batch of pages from Per-CPU-Pages(PCP) back to buddy, > the zone->lock is held and then pages are chosen from PCP's migratetype > list. While there is actually no need to do this 'choose part' under > lock since it's PCP pag

Re: [PATCH v2 1/2] free_pcppages_bulk: do not hold lock when picking pages to free

2018-02-15 Thread Mel Gorman
On Thu, Jan 25, 2018 at 03:21:44PM +0800, Aaron Lu wrote: > When freeing a batch of pages from Per-CPU-Pages(PCP) back to buddy, > the zone->lock is held and then pages are chosen from PCP's migratetype > list. While there is actually no need to do this 'choose part' under > lock since it's PCP pag

[PATCH v2 1/2] free_pcppages_bulk: do not hold lock when picking pages to free

2018-01-24 Thread Aaron Lu
When freeing a batch of pages from Per-CPU-Pages(PCP) back to buddy, the zone->lock is held and then pages are chosen from PCP's migratetype list. While there is actually no need to do this 'choose part' under lock since it's PCP pages, the only CPU that can touch them is us and irq is also disable