From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
Mel Gorman <mgorman@suse.de>,
Andrea Arcangeli <aarcange@redhat.com>,
Rik van Riel <riel@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Hugh Dickins <hughd@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Paul Turner <pjt@google.com>, Hillf Danton <dhillf@gmail.com>,
David Rientjes <rientjes@google.com>,
Lee Schermerhorn <Lee.Schermerhorn@hp.com>,
Alex Shi <lkml.alex@gmail.com>,
Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] sched: Fix task_numa_fault() + KSM crash
Date: Thu, 13 Dec 2012 19:27:26 +0530 [thread overview]
Message-ID: <20121213135726.GE29086@linux.vnet.ibm.com> (raw)
In-Reply-To: <20121210124458.GA10252@gmail.com>
* Ingo Molnar <mingo@kernel.org> [2012-12-10 13:44:58]:
> Srikar Dronamraju reported that the following assert triggers on
> his box:
>
> kernel BUG at ../kernel/sched/fair.c:2371!
>
> Call Trace:
> [<ffffffff8113cd0e>] __do_numa_page+0xde/0x160
> [<ffffffff8113de9e>] handle_pte_fault+0x32e/0xcd0
> [<ffffffffa01c22c0>] ? drop_large_spte+0x30/0x30 [kvm]
> [<ffffffffa01bf215>] ? kvm_set_spte_hva+0x25/0x30 [kvm]
> [<ffffffff8113eab9>] handle_mm_fault+0x279/0x760
> [<ffffffff8115c024>] break_ksm+0x74/0xa0
> [<ffffffff8115c222>] break_cow+0xa2/0xb0
> [<ffffffff8115e38c>] ksm_scan_thread+0xb5c/0xd50
> [<ffffffff810771c0>] ? wake_up_bit+0x40/0x40
> [<ffffffff8115d830>] ? run_store+0x340/0x340
> [<ffffffff8107692e>] kthread+0xce/0xe0
>
> This means that task_numa_fault() was called for a kernel thread
> which has no fault tracking.
>
> This scenario is actually possible if a kernel thread does
> fault processing on behalf of a user-space task - ignore
> the page fault in that case.
>
> Also remove the (now never triggering) assert and robustify
> a nearby assert.
>
I do confirm that with this change, I dont see the assert anymore.
> Reported-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Cc: Andrea Arcangeli <aarcange@redhat.com>
> Cc: Rik van Riel <riel@redhat.com>
> Cc: Mel Gorman <mgorman@suse.de>
> Cc: Hugh Dickins <hughd@google.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Signed-off-by: Ingo Molnar <mingo@kernel.org>
> ---
> kernel/sched/fair.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 9d11a8a..61c7a10 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -2351,6 +2351,13 @@ void task_numa_fault(unsigned long addr, int node, int last_cpupid, int pages, b
> int priv;
> int idx;
>
> + /*
> + * Kernel threads might not have an mm but might still
> + * do fault processing (such as KSM):
> + */
> + if (!p->numa_faults)
> + return;
> +
> if (last_cpupid != cpu_pid_to_cpupid(-1, -1)) {
> /* Did we access it last time around? */
> if (last_pid == this_pid) {
> @@ -2367,8 +2374,8 @@ void task_numa_fault(unsigned long addr, int node, int last_cpupid, int pages, b
>
> idx = 2*node + priv;
>
> - WARN_ON_ONCE(last_cpu == -1 || node == -1);
> - BUG_ON(!p->numa_faults);
> + if (WARN_ON_ONCE(last_cpu == -1 || node == -1))
> + return;
>
> p->numa_faults_curr[idx] += pages;
> shared_fault_tick(p, node, last_cpu, pages);
>
next prev parent reply other threads:[~2012-12-13 14:28 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-07 10:23 [PATCH 00/49] Automatic NUMA Balancing v10 Mel Gorman
2012-12-07 10:23 ` [PATCH 01/49] x86: mm: only do a local tlb flush in ptep_set_access_flags() Mel Gorman
2012-12-07 10:23 ` [PATCH 02/49] x86: mm: drop TLB flush from ptep_set_access_flags Mel Gorman
2012-12-07 10:23 ` [PATCH 03/49] mm,generic: only flush the local TLB in ptep_set_access_flags Mel Gorman
2012-12-07 10:23 ` [PATCH 04/49] x86/mm: Introduce pte_accessible() Mel Gorman
2012-12-07 10:23 ` [PATCH 05/49] mm: Only flush the TLB when clearing an accessible pte Mel Gorman
2012-12-07 10:23 ` [PATCH 06/49] mm: Count the number of pages affected in change_protection() Mel Gorman
2012-12-07 10:23 ` [PATCH 07/49] mm: Optimize the TLB flush of sys_mprotect() and change_protection() users Mel Gorman
2012-12-07 10:23 ` [PATCH 08/49] mm: compaction: Move migration fail/success stats to migrate.c Mel Gorman
2012-12-07 10:23 ` [PATCH 09/49] mm: migrate: Add a tracepoint for migrate_pages Mel Gorman
2012-12-07 10:23 ` [PATCH 10/49] mm: compaction: Add scanned and isolated counters for compaction Mel Gorman
2012-12-07 10:23 ` [PATCH 11/49] mm: numa: define _PAGE_NUMA Mel Gorman
2012-12-07 10:23 ` [PATCH 12/49] mm: numa: pte_numa() and pmd_numa() Mel Gorman
2012-12-07 10:23 ` [PATCH 13/49] mm: numa: Support NUMA hinting page faults from gup/gup_fast Mel Gorman
2012-12-07 10:23 ` [PATCH 14/49] mm: numa: split_huge_page: transfer the NUMA type from the pmd to the pte Mel Gorman
2012-12-07 10:23 ` [PATCH 15/49] mm: numa: Create basic numa page hinting infrastructure Mel Gorman
2012-12-07 10:23 ` [PATCH 16/49] mm: mempolicy: Make MPOL_LOCAL a real policy Mel Gorman
2012-12-07 10:23 ` [PATCH 17/49] mm: mempolicy: Add MPOL_NOOP Mel Gorman
2012-12-07 10:23 ` [PATCH 18/49] mm: mempolicy: Check for misplaced page Mel Gorman
2012-12-07 10:23 ` [PATCH 19/49] mm: migrate: Introduce migrate_misplaced_page() Mel Gorman
2012-12-07 10:23 ` [PATCH 20/49] mm: migrate: Drop the misplaced pages reference count if the target node is full Mel Gorman
2012-12-07 10:23 ` [PATCH 21/49] mm: mempolicy: Use _PAGE_NUMA to migrate pages Mel Gorman
2012-12-07 10:23 ` [PATCH 22/49] mm: mempolicy: Add MPOL_MF_LAZY Mel Gorman
2013-01-05 5:18 ` Simon Jeons
2013-01-07 15:14 ` Mel Gorman
2012-12-07 10:23 ` [PATCH 23/49] mm: mempolicy: Implement change_prot_numa() in terms of change_protection() Mel Gorman
2012-12-07 10:23 ` [PATCH 24/49] mm: mempolicy: Hide MPOL_NOOP and MPOL_MF_LAZY from userspace for now Mel Gorman
2012-12-07 10:23 ` [PATCH 25/49] mm: numa: Add fault driven placement and migration Mel Gorman
2013-01-04 11:56 ` Simon Jeons
2012-12-07 10:23 ` [PATCH 26/49] mm: sched: numa: Implement constant, per task Working Set Sampling (WSS) rate Mel Gorman
2012-12-07 10:23 ` [PATCH 27/49] sched, numa, mm: Count WS scanning against present PTEs, not virtual memory ranges Mel Gorman
2012-12-07 10:23 ` [PATCH 28/49] mm: sched: numa: Implement slow start for working set sampling Mel Gorman
2012-12-07 10:23 ` [PATCH 29/49] mm: numa: Add pte updates, hinting and migration stats Mel Gorman
2013-01-04 11:42 ` Simon Jeons
2013-01-07 15:29 ` Mel Gorman
2012-12-07 10:23 ` [PATCH 30/49] mm: numa: Migrate on reference policy Mel Gorman
2012-12-07 10:23 ` [PATCH 31/49] mm: numa: Migrate pages handled during a pmd_numa hinting fault Mel Gorman
2012-12-07 10:23 ` [PATCH 32/49] mm: numa: Structures for Migrate On Fault per NUMA migration rate limiting Mel Gorman
2012-12-07 10:23 ` [PATCH 33/49] mm: numa: Rate limit the amount of memory that is migrated between nodes Mel Gorman
2012-12-07 10:23 ` [PATCH 34/49] mm: numa: Rate limit setting of pte_numa if node is saturated Mel Gorman
2012-12-07 10:23 ` [PATCH 35/49] sched: numa: Slowly increase the scanning period as NUMA faults are handled Mel Gorman
2012-12-07 10:23 ` [PATCH 36/49] mm: numa: Introduce last_nid to the page frame Mel Gorman
2012-12-07 10:23 ` [PATCH 37/49] mm: numa: split_huge_page: Transfer last_nid on tail page Mel Gorman
2012-12-07 10:23 ` [PATCH 38/49] mm: numa: migrate: Set last_nid on newly allocated page Mel Gorman
2012-12-07 10:23 ` [PATCH 39/49] mm: numa: Use a two-stage filter to restrict pages being migrated for unlikely task<->node relationships Mel Gorman
2012-12-07 10:23 ` [PATCH 40/49] mm: sched: Adapt the scanning rate if a NUMA hinting fault does not migrate Mel Gorman
2012-12-07 10:23 ` [PATCH 41/49] mm: sched: numa: Control enabling and disabling of NUMA balancing Mel Gorman
2012-12-07 10:23 ` [PATCH 42/49] mm: sched: numa: Control enabling and disabling of NUMA balancing if !SCHED_DEBUG Mel Gorman
2012-12-07 10:23 ` [PATCH 43/49] mm: sched: numa: Delay PTE scanning until a task is scheduled on a new node Mel Gorman
2012-12-07 10:23 ` [PATCH 44/49] mm: numa: Add THP migration for the NUMA working set scanning fault case Mel Gorman
[not found] ` <20130105084229.GA3208@hacker.(null)>
2013-01-07 15:37 ` Mel Gorman
2012-12-07 10:23 ` [PATCH 45/49] mm: numa: Add THP migration for the NUMA working set scanning fault case build fix Mel Gorman
2012-12-07 10:23 ` [PATCH 46/49] mm: numa: Account for failed allocations and isolations as migration failures Mel Gorman
2012-12-07 10:23 ` [PATCH 47/49] mm: migrate: Account a transhuge page properly when rate limiting Mel Gorman
2012-12-07 10:23 ` [PATCH 48/49] mm/rmap: Convert the struct anon_vma::mutex to an rwsem Mel Gorman
2012-12-07 10:23 ` [PATCH 49/49] mm/rmap, migration: Make rmap_walk_anon() and try_to_unmap_anon() more scalable Mel Gorman
2012-12-07 11:01 ` [PATCH 00/49] Automatic NUMA Balancing v10 Ingo Molnar
2012-12-09 20:36 ` Mel Gorman
2012-12-09 21:17 ` Kirill A. Shutemov
2012-12-10 8:44 ` Mel Gorman
2012-12-10 5:07 ` Srikar Dronamraju
2012-12-10 6:28 ` Srikar Dronamraju
2012-12-10 12:44 ` [PATCH] sched: Fix task_numa_fault() + KSM crash Ingo Molnar
2012-12-13 13:57 ` Srikar Dronamraju [this message]
2012-12-10 8:46 ` [PATCH 00/49] Automatic NUMA Balancing v10 Mel Gorman
2012-12-10 12:35 ` Ingo Molnar
2012-12-10 11:39 ` Ingo Molnar
2012-12-10 11:53 ` Ingo Molnar
2012-12-10 15:24 ` Mel Gorman
2012-12-11 1:02 ` Mel Gorman
2012-12-11 8:52 ` Ingo Molnar
2012-12-11 9:18 ` Ingo Molnar
2012-12-11 15:22 ` Mel Gorman
2012-12-11 16:30 ` Mel Gorman
2012-12-17 10:33 ` Ingo Molnar
2012-12-10 16:42 ` Srikar Dronamraju
2012-12-10 19:23 ` Ingo Molnar
2012-12-10 23:35 ` Srikar Dronamraju
2012-12-10 23:40 ` Srikar Dronamraju
2012-12-13 13:21 ` Srikar Dronamraju
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