Messages in this thread | | | Date | Tue, 25 Feb 2014 19:35:22 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v2] mm: per-thread vma caching |
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On Tue, Feb 25, 2014 at 10:16:46AM -0800, Davidlohr Bueso wrote: > +void vmacache_update(struct mm_struct *mm, unsigned long addr, > + struct vm_area_struct *newvma) > +{ > + /* > + * Hash based on the page number. Provides a good > + * hit rate for workloads with good locality and > + * those with random accesses as well. > + */ > + int idx = (addr >> PAGE_SHIFT) & 3;
% VMACACHE_SIZE
perhaps? GCC should turn that into a mask for all sensible values I would think.
Barring that I think something like:
#define VMACACHE_BITS 2 #define VMACACHE_SIZE (1U << VMACACHE_BITS) #define VMACACHE_MASK (VMACACHE_SIZE - 1)
Might do I suppose.
> + current->vmacache[idx] = newvma; > +} > -- > 1.8.1.4 > > >
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