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| author | Davidlohr Bueso <davidlohr@hp.com> | 2014-06-04 16:06:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-04 16:53:57 -0700 |
| commit | 4f115147ff802267d0aa41e361c5aa5bd933d896 (patch) | |
| tree | 27afdf3f60c21fde601df63d9e9998b0c758a3fe /mm/vmacache.c | |
| parent | 6f04f48dc9c0433e2bb687f5f7f7af1aba97b04d (diff) | |
| download | lwn-4f115147ff802267d0aa41e361c5aa5bd933d896.tar.gz lwn-4f115147ff802267d0aa41e361c5aa5bd933d896.zip | |
mm,vmacache: add debug data
Introduce a CONFIG_DEBUG_VM_VMACACHE option to enable counting the cache
hit rate -- exported in /proc/vmstat.
Any updates to the caching scheme needs this kind of data, thus it can
save some work re-implementing the counting all the time.
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmacache.c')
| -rw-r--r-- | mm/vmacache.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/mm/vmacache.c b/mm/vmacache.c index 1037a3bab505..658ed3b3e38d 100644 --- a/mm/vmacache.c +++ b/mm/vmacache.c @@ -78,6 +78,8 @@ struct vm_area_struct *vmacache_find(struct mm_struct *mm, unsigned long addr) if (!vmacache_valid(mm)) return NULL; + count_vm_vmacache_event(VMACACHE_FIND_CALLS); + for (i = 0; i < VMACACHE_SIZE; i++) { struct vm_area_struct *vma = current->vmacache[i]; @@ -85,8 +87,10 @@ struct vm_area_struct *vmacache_find(struct mm_struct *mm, unsigned long addr) continue; if (WARN_ON_ONCE(vma->vm_mm != mm)) break; - if (vma->vm_start <= addr && vma->vm_end > addr) + if (vma->vm_start <= addr && vma->vm_end > addr) { + count_vm_vmacache_event(VMACACHE_FIND_HITS); return vma; + } } return NULL; @@ -102,11 +106,15 @@ struct vm_area_struct *vmacache_find_exact(struct mm_struct *mm, if (!vmacache_valid(mm)) return NULL; + count_vm_vmacache_event(VMACACHE_FIND_CALLS); + for (i = 0; i < VMACACHE_SIZE; i++) { struct vm_area_struct *vma = current->vmacache[i]; - if (vma && vma->vm_start == start && vma->vm_end == end) + if (vma && vma->vm_start == start && vma->vm_end == end) { + count_vm_vmacache_event(VMACACHE_FIND_HITS); return vma; + } } return NULL; |