On Tue, Nov 22, 2011 at 1:08 PM, Gilad Ben-Yossef <gilad@xxxxxxxxxxxxx> wrote:
> Calculate a cpumask of CPUs with per-cpu pages in any zone and only send an IPI requesting CPUs to drain these pages to the buddy allocator if they actually have pages when asked to flush.
>
> The code path of memory allocation failure for CPUMASK_OFFSTACK=y config was tested using fault injection framework.
>
> Signed-off-by: Gilad Ben-Yossef <gilad@xxxxxxxxxxxxx>
> Acked-by: Christoph Lameter <cl@xxxxxxxxx>
> CC: Chris Metcalf <cmetcalf@xxxxxxxxxx>
> CC: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> CC: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> CC: Russell King <linux@xxxxxxxxxxxxxxxx>
> CC: linux-mm@xxxxxxxxx
> CC: Pekka Enberg <penberg@xxxxxxxxxx>
> CC: Matt Mackall <mpm@xxxxxxxxxxx>
> CC: Sasha Levin <levinsasha928@xxxxxxxxx>
> CC: Rik van Riel <riel@xxxxxxxxxx>
> CC: Andi Kleen <andi@xxxxxxxxxxxxxx>
I'm adding Mel and Andrew to CC.
> ---
> mm/page_alloc.c | 18 +++++++++++++++++-
> 1 files changed, 17 insertions(+), 1 deletions(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 9dd443d..a3efdf1 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -1119,7 +1119,23 @@ void drain_local_pages(void *arg)
> */
> void drain_all_pages(void)
> {
> - on_each_cpu(drain_local_pages, NULL, 1);
> + int cpu;
> + struct zone *zone;
> + cpumask_var_t cpus;
> + struct per_cpu_pageset *pcp;
> +
> + if (likely(zalloc_cpumask_var(&cpus, GFP_ATOMIC))) {
__GFP_NOWARN
> + for_each_online_cpu(cpu) {
> + for_each_populated_zone(zone) {
> + pcp = per_cpu_ptr(zone->pageset, cpu);
> + if (pcp->pcp.count)
> + cpumask_set_cpu(cpu, cpus);
> + }
> + }
> + on_each_cpu_mask(cpus, drain_local_pages, NULL, 1);
> + free_cpumask_var(cpus);
> + } else
> + on_each_cpu(drain_local_pages, NULL, 1);
> }
>
> #ifdef CONFIG_HIBERNATION
Acked-by: Pekka Enberg <penberg@xxxxxxxxxx>
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