From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx178.postini.com [74.125.245.178]) by kanga.kvack.org (Postfix) with SMTP id 08F7B6B0083 for ; Sun, 2 Dec 2012 13:44:33 -0500 (EST) Received: by mail-ea0-f169.google.com with SMTP id a12so1082361eaa.14 for ; Sun, 02 Dec 2012 10:44:33 -0800 (PST) From: Ingo Molnar Subject: [PATCH 17/52] mm/numa: Add pte updates, hinting and migration stats Date: Sun, 2 Dec 2012 19:43:09 +0100 Message-Id: <1354473824-19229-18-git-send-email-mingo@kernel.org> In-Reply-To: <1354473824-19229-1-git-send-email-mingo@kernel.org> References: <1354473824-19229-1-git-send-email-mingo@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Peter Zijlstra , Paul Turner , Lee Schermerhorn , Christoph Lameter , Rik van Riel , Mel Gorman , Andrew Morton , Andrea Arcangeli , Linus Torvalds , Thomas Gleixner , Johannes Weiner , Hugh Dickins , Alex Shi , Srikar Dronamraju , Aneesh Kumar From: Mel Gorman It is tricky to quantify the basic cost of automatic NUMA placement in a meaningful manner. This patch adds some vmstats that can be used as part of a basic costing model. u = basic unit = sizeof(void *) Ca = cost of struct page access = sizeof(struct page) / u Cpte = Cost PTE access = Ca Cupdate = Cost PTE update = (2 * Cpte) + (2 * Wlock) where Cpte is incurred twice for a read and a write and Wlock is a constant representing the cost of taking or releasing a lock Cnumahint = Cost of a minor page fault = some high constant e.g. 1000 Cpagerw = Cost to read or write a full page = Ca + PAGE_SIZE/u Ci = Cost of page isolation = Ca + Wi where Wi is a constant that should reflect the approximate cost of the locking operation Cpagecopy = Cpagerw + (Cpagerw * Wnuma) + Ci + (Ci * Wnuma) where Wnuma is the approximate NUMA factor. 1 is local. 1.2 would imply that remote accesses are 20% more expensive Balancing cost = Cpte * numa_pte_updates + Cnumahint * numa_hint_faults + Ci * numa_pages_migrated + Cpagecopy * numa_pages_migrated Note that numa_pages_migrated is used as a measure of how many pages were isolated even though it would miss pages that failed to migrate. A vmstat counter could have been added for it but the isolation cost is pretty marginal in comparison to the overall cost so it seemed overkill. The ideal way to measure automatic placement benefit would be to count the number of remote accesses versus local accesses and do something like benefit = (remote_accesses_before - remove_access_after) * Wnuma but the information is not readily available. As a workload converges, the expection would be that the number of remote numa hints would reduce to 0. convergence = numa_hint_faults_local / numa_hint_faults where this is measured for the last N number of numa hints recorded. When the workload is fully converged the value is 1. This can measure if the placement policy is converging and how fast it is doing it. Signed-off-by: Mel Gorman Acked-by: Rik van Riel Cc: Johannes Weiner Cc: Hugh Dickins Cc: Paul Turner Cc: Lee Schermerhorn Cc: Alex Shi Cc: Srikar Dronamraju Cc: Aneesh Kumar Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Andrea Arcangeli Signed-off-by: Ingo Molnar --- include/linux/vm_event_item.h | 6 ++++++ include/linux/vmstat.h | 8 ++++++++ mm/huge_memory.c | 1 + mm/memory.c | 14 ++++++++++++++ mm/mempolicy.c | 2 ++ mm/migrate.c | 3 ++- mm/vmstat.c | 6 ++++++ 7 files changed, 39 insertions(+), 1 deletion(-) diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h index b94bafd..bf1cb85 100644 --- a/include/linux/vm_event_item.h +++ b/include/linux/vm_event_item.h @@ -38,6 +38,12 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, KSWAPD_LOW_WMARK_HIT_QUICKLY, KSWAPD_HIGH_WMARK_HIT_QUICKLY, KSWAPD_SKIP_CONGESTION_WAIT, PAGEOUTRUN, ALLOCSTALL, PGROTATED, +#ifdef CONFIG_NUMA_BALANCING + NUMA_PTE_UPDATES, + NUMA_HINT_FAULTS, + NUMA_HINT_FAULTS_LOCAL, + NUMA_PAGE_MIGRATE, +#endif #ifdef CONFIG_MIGRATION PGMIGRATE_SUCCESS, PGMIGRATE_FAIL, #endif diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h index 92a86b2..a13291f 100644 --- a/include/linux/vmstat.h +++ b/include/linux/vmstat.h @@ -80,6 +80,14 @@ static inline void vm_events_fold_cpu(int cpu) #endif /* CONFIG_VM_EVENT_COUNTERS */ +#ifdef CONFIG_NUMA_BALANCING +#define count_vm_numa_event(x) count_vm_event(x) +#define count_vm_numa_events(x, y) count_vm_events(x, y) +#else +#define count_vm_numa_event(x) do {} while (0) +#define count_vm_numa_events(x, y) do {} while (0) +#endif /* CONFIG_NUMA_BALANCING */ + #define __count_zone_vm_events(item, zone, delta) \ __count_vm_events(item##_NORMAL - ZONE_NORMAL + \ zone_idx(zone), delta) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index d79f7a5..3566820 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1034,6 +1034,7 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, page = pmd_page(pmd); get_page(page); spin_unlock(&mm->page_table_lock); + count_vm_numa_event(NUMA_HINT_FAULTS); target_nid = mpol_misplaced(page, vma, haddr); if (target_nid == -1) diff --git a/mm/memory.c b/mm/memory.c index 174f006..1ff36b1 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3476,6 +3476,7 @@ int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, set_pte_at(mm, addr, ptep, pte); update_mmu_cache(vma, addr, ptep); + count_vm_numa_event(NUMA_HINT_FAULTS); page = vm_normal_page(vma, addr, pte); if (!page) { pte_unmap_unlock(ptep, ptl); @@ -3484,6 +3485,8 @@ int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, get_page(page); current_nid = page_to_nid(page); + if (current_nid == numa_node_id()) + count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL); target_nid = mpol_misplaced(page, vma, addr); pte_unmap_unlock(ptep, ptl); if (target_nid == -1) { @@ -3514,6 +3517,10 @@ int do_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long offset; spinlock_t *ptl; bool numa = false; + int local_nid = numa_node_id(); + int curr_nid; + unsigned long nr_faults = 0; + unsigned long nr_faults_local = 0; spin_lock(&mm->page_table_lock); pmd = *pmdp; @@ -3553,9 +3560,16 @@ int do_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, page = vm_normal_page(vma, addr, pteval); if (unlikely(!page)) continue; + curr_nid = page_to_nid(page); + + nr_faults++; + if (curr_nid == local_nid) + nr_faults_local++; } pte_unmap_unlock(orig_pte, ptl); + count_vm_numa_events(NUMA_HINT_FAULTS, nr_faults); + count_vm_numa_events(NUMA_HINT_FAULTS_LOCAL, nr_faults_local); return 0; } diff --git a/mm/mempolicy.c b/mm/mempolicy.c index a7a62fe..516491f 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -583,6 +583,8 @@ unsigned long change_prot_numa(struct vm_area_struct *vma, BUILD_BUG_ON(_PAGE_NUMA != _PAGE_PROTNONE); nr_updated = change_protection(vma, addr, end, vma->vm_page_prot, 0, 1); + if (nr_updated) + count_vm_numa_events(NUMA_PTE_UPDATES, nr_updated); return nr_updated; } diff --git a/mm/migrate.c b/mm/migrate.c index d168aec..cdd07c7 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1511,7 +1511,8 @@ int migrate_misplaced_page(struct page *page, int node) if (nr_remaining) { putback_lru_pages(&migratepages); isolated = 0; - } + } else + count_vm_numa_event(NUMA_PAGE_MIGRATE); } BUG_ON(!list_empty(&migratepages)); out: diff --git a/mm/vmstat.c b/mm/vmstat.c index 3a067fa..c0f1f6d 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -774,6 +774,12 @@ const char * const vmstat_text[] = { "pgrotated", +#ifdef CONFIG_NUMA_BALANCING + "numa_pte_updates", + "numa_hint_faults", + "numa_hint_faults_local", + "numa_pages_migrated", +#endif #ifdef CONFIG_MIGRATION "pgmigrate_success", "pgmigrate_fail", -- 1.7.11.7 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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