Messages in this thread | | | Subject | Re: [PATCH] mm/vmstats: add counters for the page frag cache | From | Konstantin Khlebnikov <> | Date | Fri, 1 Sep 2017 12:12:36 +0300 |
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IMHO that's too much counters. Per-node NR_FRAGMENT_PAGES should be enough for guessing what's going on. Perf probes provides enough features for furhter debugging.
On 01.09.2017 02:37, Kyeongdon Kim wrote: > There was a memory leak problem when we did stressful test > on Android device. > The root cause of this was from page_frag_cache alloc > and it was very hard to find out. > > We add to count the page frag allocation and free with function call. > The gap between pgfrag_alloc and pgfrag_free is good to to calculate > for the amount of page. > The gap between pgfrag_alloc_calls and pgfrag_free_calls is for > sub-indicator. > They can see trends of memory usage during the test. > Without it, it's difficult to check page frag usage so I believe we > should add it. > > Signed-off-by: Kyeongdon Kim <kyeongdon.kim@lge.com> > --- > include/linux/vm_event_item.h | 4 ++++ > mm/page_alloc.c | 9 +++++++-- > mm/vmstat.c | 4 ++++ > 3 files changed, 15 insertions(+), 2 deletions(-) > > diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h > index d77bc35..75425d4 100644 > --- a/include/linux/vm_event_item.h > +++ b/include/linux/vm_event_item.h > @@ -110,6 +110,10 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, > SWAP_RA, > SWAP_RA_HIT, > #endif > + PGFRAG_ALLOC, > + PGFRAG_FREE, > + PGFRAG_ALLOC_CALLS, > + PGFRAG_FREE_CALLS, > NR_VM_EVENT_ITEMS > }; > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index db2d25f..b3ddd76 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -4322,6 +4322,7 @@ void __page_frag_cache_drain(struct page *page, unsigned int count) > free_hot_cold_page(page, false); > else > __free_pages_ok(page, order); > + __count_vm_events(PGFRAG_FREE, 1 << order); > } > } > EXPORT_SYMBOL(__page_frag_cache_drain); > @@ -4338,7 +4339,7 @@ void *page_frag_alloc(struct page_frag_cache *nc, > page = __page_frag_cache_refill(nc, gfp_mask); > if (!page) > return NULL; > - > + __count_vm_events(PGFRAG_ALLOC, 1 << compound_order(page)); > #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) > /* if size can vary use size else just use PAGE_SIZE */ > size = nc->size; > @@ -4375,6 +4376,7 @@ void *page_frag_alloc(struct page_frag_cache *nc, > > nc->pagecnt_bias--; > nc->offset = offset; > + __count_vm_event(PGFRAG_ALLOC_CALLS); > > return nc->va + offset; > } > @@ -4387,8 +4389,11 @@ void page_frag_free(void *addr) > { > struct page *page = virt_to_head_page(addr); > > - if (unlikely(put_page_testzero(page))) > + if (unlikely(put_page_testzero(page))) { > + __count_vm_events(PGFRAG_FREE, 1 << compound_order(page)); > __free_pages_ok(page, compound_order(page)); > + } > + __count_vm_event(PGFRAG_FREE_CALLS); > } > EXPORT_SYMBOL(page_frag_free); > > diff --git a/mm/vmstat.c b/mm/vmstat.c > index 4bb13e7..c00fe05 100644 > --- a/mm/vmstat.c > +++ b/mm/vmstat.c > @@ -1217,6 +1217,10 @@ const char * const vmstat_text[] = { > "swap_ra", > "swap_ra_hit", > #endif > + "pgfrag_alloc", > + "pgfrag_free", > + "pgfrag_alloc_calls", > + "pgfrag_free_calls", > #endif /* CONFIG_VM_EVENTS_COUNTERS */ > }; > #endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */ >
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