Messages in this thread | | | Subject | Re: [PATCH v2] mm: per-thread vma caching | From | Davidlohr Bueso <> | Date | Tue, 25 Feb 2014 10:37:34 -0800 |
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On Tue, 2014-02-25 at 19:35 +0100, Peter Zijlstra wrote: > 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)
Hmm all that seems like an overkill.
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