From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933230AbZHDSMy (ORCPT ); Tue, 4 Aug 2009 14:12:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933216AbZHDSMw (ORCPT ); Tue, 4 Aug 2009 14:12:52 -0400 Received: from gir.skynet.ie ([193.1.99.77]:37088 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933186AbZHDSMb (ORCPT ); Tue, 4 Aug 2009 14:12:31 -0400 From: Mel Gorman To: Larry Woodman , Andrew Morton Cc: riel@redhat.com, Ingo Molnar , Peter Zijlstra , LKML , linux-mm@kvack.org, Mel Gorman Subject: [PATCH 1/4] tracing, page-allocator: Add trace events for page allocation and page freeing Date: Tue, 4 Aug 2009 19:12:23 +0100 Message-Id: <1249409546-6343-2-git-send-email-mel@csn.ul.ie> X-Mailer: git-send-email 1.6.3.3 In-Reply-To: <1249409546-6343-1-git-send-email-mel@csn.ul.ie> References: <1249409546-6343-1-git-send-email-mel@csn.ul.ie> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds trace events for the allocation and freeing of pages, including the freeing of pagevecs. Using the events, it will be known what struct page and pfns are being allocated and freed and what the call site was in many cases. The page alloc tracepoints be used as an indicator as to whether the workload was heavily dependant on the page allocator or not. You can make a guess based on vmstat but you can't get a per-process breakdown. Depending on the call path, the call_site for page allocation may be __get_free_pages() instead of a useful callsite. Instead of passing down a return address similar to slab debugging, the user should enable the stacktrace and seg-addr options to get a proper stack trace. The pagevec free tracepoint has a different usecase. It can be used to get a idea of how many pages are being dumped off the LRU and whether it is kswapd doing the work or a process doing direct reclaim. Signed-off-by: Mel Gorman Acked-by: Rik van Riel --- include/trace/events/kmem.h | 86 +++++++++++++++++++++++++++++++++++++++++++ mm/page_alloc.c | 6 ++- 2 files changed, 91 insertions(+), 1 deletions(-) diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h index 1493c54..57bf13c 100644 --- a/include/trace/events/kmem.h +++ b/include/trace/events/kmem.h @@ -225,6 +225,92 @@ TRACE_EVENT(kmem_cache_free, TP_printk("call_site=%lx ptr=%p", __entry->call_site, __entry->ptr) ); + +TRACE_EVENT(mm_page_free_direct, + + TP_PROTO(unsigned long call_site, const void *page, unsigned int order), + + TP_ARGS(call_site, page, order), + + TP_STRUCT__entry( + __field( unsigned long, call_site ) + __field( const void *, page ) + __field( unsigned int, order ) + ), + + TP_fast_assign( + __entry->call_site = call_site; + __entry->page = page; + __entry->order = order; + ), + + TP_printk("call_site=%lx page=%p pfn=%lu order=%d", + __entry->call_site, + __entry->page, + page_to_pfn((struct page *)__entry->page), + __entry->order) +); + +TRACE_EVENT(mm_pagevec_free, + + TP_PROTO(unsigned long call_site, const void *page, int order, int cold), + + TP_ARGS(call_site, page, order, cold), + + TP_STRUCT__entry( + __field( unsigned long, call_site ) + __field( const void *, page ) + __field( int, order ) + __field( int, cold ) + ), + + TP_fast_assign( + __entry->call_site = call_site; + __entry->page = page; + __entry->order = order; + __entry->cold = cold; + ), + + TP_printk("call_site=%lx page=%p pfn=%lu order=%d cold=%d", + __entry->call_site, + __entry->page, + page_to_pfn((struct page *)__entry->page), + __entry->order, + __entry->cold) +); + +TRACE_EVENT(mm_page_alloc, + + TP_PROTO(unsigned long call_site, const void *page, unsigned int order, + gfp_t gfp_flags, int migratetype), + + TP_ARGS(call_site, page, order, gfp_flags, migratetype), + + TP_STRUCT__entry( + __field( unsigned long, call_site ) + __field( const void *, page ) + __field( unsigned int, order ) + __field( gfp_t, gfp_flags ) + __field( int, migratetype ) + ), + + TP_fast_assign( + __entry->call_site = call_site; + __entry->page = page; + __entry->order = order; + __entry->gfp_flags = gfp_flags; + __entry->migratetype = migratetype; + ), + + TP_printk("call_site=%lx page=%p pfn=%lu order=%d migratetype=%d gfp_flags=%s", + __entry->call_site, + __entry->page, + page_to_pfn((struct page *)__entry->page), + __entry->order, + __entry->migratetype, + show_gfp_flags(__entry->gfp_flags)) +); + #endif /* _TRACE_KMEM_H */ /* This part must be outside protection */ diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d052abb..843bdec 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1905,6 +1905,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, zonelist, high_zoneidx, nodemask, preferred_zone, migratetype); + trace_mm_page_alloc(_RET_IP_, page, order, gfp_mask, migratetype); return page; } EXPORT_SYMBOL(__alloc_pages_nodemask); @@ -1945,13 +1946,16 @@ void __pagevec_free(struct pagevec *pvec) { int i = pagevec_count(pvec); - while (--i >= 0) + while (--i >= 0) { + trace_mm_pagevec_free(_RET_IP_, pvec->pages[i], 0, pvec->cold); free_hot_cold_page(pvec->pages[i], pvec->cold); + } } void __free_pages(struct page *page, unsigned int order) { if (put_page_testzero(page)) { + trace_mm_page_free_direct(_RET_IP_, page, order); if (order == 0) free_hot_page(page); else -- 1.6.3.3