Messages in this thread |  | | Date | Thu, 12 Dec 2013 21:41:55 +0800 | From | Alex Shi <> | Subject | Re: [PATCH 3/3] x86: mm: Account for the of CPUs that must be flushed during a TLB range flush |
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On 12/12/2013 07:55 PM, Mel Gorman wrote: > X86 TLB range flushing uses a balance point to decide if a single global TLB > flush or multiple single page flushes would perform best. This patch takes into > account how many CPUs must be flushed. > > Signed-off-by: Mel Gorman <mgorman@suse.de> > --- > arch/x86/mm/tlb.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c > index 09b8cb8..0cababa 100644 > --- a/arch/x86/mm/tlb.c > +++ b/arch/x86/mm/tlb.c > @@ -217,6 +217,9 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, > act_entries = mm->total_vm > act_entries ? act_entries : mm->total_vm; > nr_base_pages = (end - start) >> PAGE_SHIFT; > > + /* Take the number of CPUs to range flush into account */ > + nr_base_pages *= cpumask_weight(mm_cpumask(mm)); > +
flush range calculation base on per cpu, since no matter how many cpus in the process, tlb flush and refill time won't change. > /* tlb_flushall_shift is on balance point, details in commit log */ > if (nr_base_pages > act_entries || has_large_page(mm, start, end)) { > count_vm_event(NR_TLB_LOCAL_FLUSH_ALL); >
-- Thanks Alex
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