From cf40bd16fdad42c053040bcd3988f5fdedbb6c57 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Wed, 21 Jan 2009 08:12:39 +0100 Subject: lockdep: annotate reclaim context (__GFP_NOFS) Here is another version, with the incremental patch rolled up, and added reclaim context annotation to kswapd, and allocation tracing to slab allocators (which may only ever reach the page allocator in rare cases, so it is good to put annotations here too). Haven't tested this version as such, but it should be getting closer to merge worthy ;) -- After noticing some code in mm/filemap.c accidentally perform a __GFP_FS allocation when it should not have been, I thought it might be a good idea to try to catch this kind of thing with lockdep. I coded up a little idea that seems to work. Unfortunately the system has to actually be in __GFP_FS page reclaim, then take the lock, before it will mark it. But at least that might still be some orders of magnitude more common (and more debuggable) than an actual deadlock condition, so we have some improvement I hope (the concept is no less complete than discovery of a lock's interrupt contexts). I guess we could even do the same thing with __GFP_IO (normal reclaim), and even GFP_NOIO locks too... but filesystems will have the most locks and fiddly code paths, so let's start there and see how it goes. It *seems* to work. I did a quick test. ================================= [ INFO: inconsistent lock state ] 2.6.28-rc6-00007-ged31348-dirty #26 --------------------------------- inconsistent {in-reclaim-W} -> {ov-reclaim-W} usage. modprobe/8526 [HC0[0]:SC0[0]:HE1:SE1] takes: (testlock){--..}, at: [] brd_init+0x55/0x216 [brd] {in-reclaim-W} state was registered at: [] __lock_acquire+0x75b/0x1a60 [] lock_acquire+0x91/0xc0 [] mutex_lock_nested+0xb1/0x310 [] brd_init+0x2b/0x216 [brd] [] _stext+0x3b/0x170 [] sys_init_module+0xaf/0x1e0 [] system_call_fastpath+0x16/0x1b [] 0xffffffffffffffff irq event stamp: 3929 hardirqs last enabled at (3929): [] mutex_lock_nested+0x285/0x310 hardirqs last disabled at (3928): [] mutex_lock_nested+0x59/0x310 softirqs last enabled at (3732): [] sk_filter+0x83/0xe0 softirqs last disabled at (3730): [] sk_filter+0x16/0xe0 other info that might help us debug this: 1 lock held by modprobe/8526: #0: (testlock){--..}, at: [] brd_init+0x55/0x216 [brd] stack backtrace: Pid: 8526, comm: modprobe Not tainted 2.6.28-rc6-00007-ged31348-dirty #26 Call Trace: [] print_usage_bug+0x193/0x1d0 [] mark_lock+0xaf0/0xca0 [] mark_held_locks+0x55/0xc0 [] ? brd_init+0x0/0x216 [brd] [] trace_reclaim_fs+0x2a/0x60 [] __alloc_pages_internal+0x475/0x580 [] ? mutex_lock_nested+0x26e/0x310 [] ? brd_init+0x0/0x216 [brd] [] brd_init+0x6a/0x216 [brd] [] ? brd_init+0x0/0x216 [brd] [] _stext+0x3b/0x170 [] ? mutex_unlock+0x9/0x10 [] ? __mutex_unlock_slowpath+0x10d/0x180 [] ? trace_hardirqs_on_caller+0x12c/0x190 [] sys_init_module+0xaf/0x1e0 [] system_call_fastpath+0x16/0x1b Signed-off-by: Nick Piggin Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- mm/page_alloc.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 5675b3073854..22b15a4cde8a 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1479,6 +1479,8 @@ __alloc_pages_internal(gfp_t gfp_mask, unsigned int order, unsigned long did_some_progress; unsigned long pages_reclaimed = 0; + lockdep_trace_alloc(gfp_mask); + might_sleep_if(wait); if (should_fail_alloc_page(gfp_mask, order)) @@ -1578,12 +1580,15 @@ nofail_alloc: */ cpuset_update_task_memory_state(); p->flags |= PF_MEMALLOC; + + lockdep_set_current_reclaim_state(gfp_mask); reclaim_state.reclaimed_slab = 0; p->reclaim_state = &reclaim_state; did_some_progress = try_to_free_pages(zonelist, order, gfp_mask); p->reclaim_state = NULL; + lockdep_clear_current_reclaim_state(); p->flags &= ~PF_MEMALLOC; cond_resched(); -- cgit v1.2.3 From a70f730282019f487aa33a84e5ac9a5e89c5abd0 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 13 Mar 2009 14:49:46 +1030 Subject: cpumask: replace node_to_cpumask with cpumask_of_node. Impact: cleanup node_to_cpumask (and the blecherous node_to_cpumask_ptr which contained a declaration) are replaced now everyone implements cpumask_of_node. Signed-off-by: Rusty Russell --- mm/page_alloc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 5c44ed49ca93..a92b0975b9a5 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2134,7 +2134,7 @@ static int find_next_best_node(int node, nodemask_t *used_node_mask) int n, val; int min_val = INT_MAX; int best_node = -1; - node_to_cpumask_ptr(tmp, 0); + const struct cpumask *tmp = cpumask_of_node(0); /* Use the local node if we haven't already */ if (!node_isset(node, *used_node_mask)) { @@ -2155,8 +2155,8 @@ static int find_next_best_node(int node, nodemask_t *used_node_mask) val += (n < node); /* Give preference to headless and unused nodes */ - node_to_cpumask_ptr_next(tmp, n); - if (!cpus_empty(*tmp)) + tmp = cpumask_of_node(n); + if (!cpumask_empty(tmp)) val += PENALTY_FOR_NODE_WITH_CPUS; /* Slight preference for less loaded node */ -- cgit v1.2.3 From e713a21d8251a4c91772f592af46407dfb0b2e4f Mon Sep 17 00:00:00 2001 From: Alexey Zaytsev Date: Sat, 10 Jan 2009 02:47:57 +0300 Subject: trivial: Fix dubious bitwise 'or' usage spotted by sparse. It doesn't change the semantics, but it looks like the logical 'or' was meant to be used here. Signed-off-by: Alexey Zaytsev Signed-off-by: Jiri Kosina --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 5c44ed49ca93..daa36f103e77 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -331,7 +331,7 @@ static int destroy_compound_page(struct page *page, unsigned long order) for (i = 1; i < nr_pages; i++) { struct page *p = page + i; - if (unlikely(!PageTail(p) | (p->first_page != page))) { + if (unlikely(!PageTail(p) || (p->first_page != page))) { bad_page(page); bad++; } -- cgit v1.2.3 From ee99c71c59f897436ec65debb99372b3146f9985 Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Tue, 31 Mar 2009 15:19:31 -0700 Subject: mm: introduce for_each_populated_zone() macro Impact: cleanup In almost cases, for_each_zone() is used with populated_zone(). It's because almost function doesn't need memoryless node information. Therefore, for_each_populated_zone() can help to make code simplify. This patch has no functional change. [akpm@linux-foundation.org: small cleanup] Signed-off-by: KOSAKI Motohiro Cc: KAMEZAWA Hiroyuki Cc: Mel Gorman Reviewed-by: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 26 +++++--------------------- 1 file changed, 5 insertions(+), 21 deletions(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a3803ea8c27d..cbd532161f68 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -922,13 +922,10 @@ static void drain_pages(unsigned int cpu) unsigned long flags; struct zone *zone; - for_each_zone(zone) { + for_each_populated_zone(zone) { struct per_cpu_pageset *pset; struct per_cpu_pages *pcp; - if (!populated_zone(zone)) - continue; - pset = zone_pcp(zone, cpu); pcp = &pset->pcp; @@ -1879,10 +1876,7 @@ void show_free_areas(void) int cpu; struct zone *zone; - for_each_zone(zone) { - if (!populated_zone(zone)) - continue; - + for_each_populated_zone(zone) { show_node(zone); printk("%s per-cpu:\n", zone->name); @@ -1922,12 +1916,9 @@ void show_free_areas(void) global_page_state(NR_PAGETABLE), global_page_state(NR_BOUNCE)); - for_each_zone(zone) { + for_each_populated_zone(zone) { int i; - if (!populated_zone(zone)) - continue; - show_node(zone); printk("%s" " free:%lukB" @@ -1967,12 +1958,9 @@ void show_free_areas(void) printk("\n"); } - for_each_zone(zone) { + for_each_populated_zone(zone) { unsigned long nr[MAX_ORDER], flags, order, total = 0; - if (!populated_zone(zone)) - continue; - show_node(zone); printk("%s: ", zone->name); @@ -2784,11 +2772,7 @@ static int __cpuinit process_zones(int cpu) node_set_state(node, N_CPU); /* this node has a cpu */ - for_each_zone(zone) { - - if (!populated_zone(zone)) - continue; - + for_each_populated_zone(zone) { zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset), GFP_KERNEL, node); if (!zone_pcp(zone, cpu)) -- cgit v1.2.3 From 327c0e968645f2601a43f5ea7c19c7b3a5fa0a34 Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Tue, 31 Mar 2009 15:23:31 -0700 Subject: vmscan: fix it to take care of nodemask try_to_free_pages() is used for the direct reclaim of up to SWAP_CLUSTER_MAX pages when watermarks are low. The caller to alloc_pages_nodemask() can specify a nodemask of nodes that are allowed to be used but this is not passed to try_to_free_pages(). This can lead to unnecessary reclaim of pages that are unusable by the caller and int the worst case lead to allocation failure as progress was not been make where it is needed. This patch passes the nodemask used for alloc_pages_nodemask() to try_to_free_pages(). Reviewed-by: KOSAKI Motohiro Acked-by: Mel Gorman Signed-off-by: KAMEZAWA Hiroyuki Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index cbd532161f68..0284e528748d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1582,7 +1582,8 @@ nofail_alloc: reclaim_state.reclaimed_slab = 0; p->reclaim_state = &reclaim_state; - did_some_progress = try_to_free_pages(zonelist, order, gfp_mask); + did_some_progress = try_to_free_pages(zonelist, order, + gfp_mask, nodemask); p->reclaim_state = NULL; lockdep_clear_current_reclaim_state(); -- cgit v1.2.3