Subject: + mmvmacache-add-debug-data.patch added to -mm tree To: davidlohr@xxxxxx,aswin@xxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Tue, 15 Apr 2014 13:52:20 -0700 The patch titled Subject: mm,vmacache: add debug data has been added to the -mm tree. Its filename is mmvmacache-add-debug-data.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mmvmacache-add-debug-data.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mmvmacache-add-debug-data.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Davidlohr Bueso <davidlohr@xxxxxx> Subject: 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@xxxxxx> Cc: Aswin Chandramouleeswaran <aswin@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/vm_event_item.h | 4 ++++ include/linux/vmstat.h | 6 ++++++ lib/Kconfig.debug | 10 ++++++++++ mm/vmacache.c | 9 ++++++++- mm/vmstat.c | 4 ++++ 5 files changed, 32 insertions(+), 1 deletion(-) diff -puN include/linux/vm_event_item.h~mmvmacache-add-debug-data include/linux/vm_event_item.h --- a/include/linux/vm_event_item.h~mmvmacache-add-debug-data +++ a/include/linux/vm_event_item.h @@ -80,6 +80,10 @@ enum vm_event_item { PGPGIN, PGPGOUT, PS NR_TLB_LOCAL_FLUSH_ALL, NR_TLB_LOCAL_FLUSH_ONE, #endif /* CONFIG_DEBUG_TLBFLUSH */ +#ifdef CONFIG_DEBUG_VM_VMACACHE + VMACACHE_FIND_CALLS, + VMACACHE_FIND_HITS, +#endif NR_VM_EVENT_ITEMS }; diff -puN include/linux/vmstat.h~mmvmacache-add-debug-data include/linux/vmstat.h --- a/include/linux/vmstat.h~mmvmacache-add-debug-data +++ a/include/linux/vmstat.h @@ -95,6 +95,12 @@ static inline void vm_events_fold_cpu(in #define count_vm_tlb_events(x, y) do { (void)(y); } while (0) #endif +#ifdef CONFIG_DEBUG_VM_VMACACHE +#define count_vm_vmacache_event(x) count_vm_event(x) +#else +#define count_vm_vmacache_event(x) do {} while (0) +#endif + #define __count_zone_vm_events(item, zone, delta) \ __count_vm_events(item##_NORMAL - ZONE_NORMAL + \ zone_idx(zone), delta) diff -puN lib/Kconfig.debug~mmvmacache-add-debug-data lib/Kconfig.debug --- a/lib/Kconfig.debug~mmvmacache-add-debug-data +++ a/lib/Kconfig.debug @@ -501,6 +501,16 @@ config DEBUG_VM If unsure, say N. +config DEBUG_VM_VMACACHE + bool "Debug VMA caching" + depends on DEBUG_VM + help + Enable this to turn on VMA caching debug information. Doing so + can cause significant overhead, so only enable it in non-production + environments. + + If unsure, say N. + config DEBUG_VM_RB bool "Debug VM red-black trees" depends on DEBUG_VM diff -puN mm/vmacache.c~mmvmacache-add-debug-data mm/vmacache.c --- a/mm/vmacache.c~mmvmacache-add-debug-data +++ a/mm/vmacache.c @@ -78,11 +78,14 @@ struct vm_area_struct *vmacache_find(str 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 <= addr && vma->vm_end > addr) { BUG_ON(vma->vm_mm != mm); + count_vm_vmacache_event(VMACACHE_FIND_HITS); return vma; } } @@ -100,11 +103,15 @@ struct vm_area_struct *vmacache_find_exa 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; diff -puN mm/vmstat.c~mmvmacache-add-debug-data mm/vmstat.c --- a/mm/vmstat.c~mmvmacache-add-debug-data +++ a/mm/vmstat.c @@ -866,6 +866,10 @@ const char * const vmstat_text[] = { "nr_tlb_local_flush_one", #endif /* CONFIG_DEBUG_TLBFLUSH */ +#ifdef CONFIG_DEBUG_VM_VMACACHE + "vmacache_find_calls", + "vmacache_find_hits", +#endif #endif /* CONFIG_VM_EVENTS_COUNTERS */ }; #endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */ _ Patches currently in -mm which might be from davidlohr@xxxxxx are mm-fix-config_debug_vm_rb-description.patch mmvmacache-add-debug-data.patch mmvmacache-optimize-overflow-system-wide-flushing.patch ipc-constify-ipc_ops.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html