From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Peter Zijlstra <peterz@infradead.org>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"minchan.kim@gmail.com" <minchan.kim@gmail.com>,
cl@linux-foundation.org,
"hugh.dickins" <hugh.dickins@tiscali.co.uk>,
Nick Piggin <nickpiggin@yahoo.com.au>,
Ingo Molnar <mingo@elte.hu>,
Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: [RFC][PATCH 6/8] mm: handle_speculative_fault()
Date: Mon, 04 Jan 2010 19:24:35 +0100 [thread overview]
Message-ID: <20100104182813.753545361@chello.nl> (raw)
In-Reply-To: 20100104182429.833180340@chello.nl
[-- Attachment #1: mm-foo-8.patch --]
[-- Type: text/plain, Size: 2857 bytes --]
Generic speculative fault handler, tries to service a pagefault
without holding mmap_sem.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
include/linux/mm.h | 2 +
mm/memory.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 60 insertions(+), 1 deletion(-)
Index: linux-2.6/mm/memory.c
===================================================================
--- linux-2.6.orig/mm/memory.c
+++ linux-2.6/mm/memory.c
@@ -1998,7 +1998,7 @@ again:
if (!*ptep)
goto out;
- if (vma_is_dead(vma, seq))
+ if (vma && vma_is_dead(vma, seq))
goto unlock;
unpin_page_tables();
@@ -3112,6 +3112,63 @@ int handle_mm_fault(struct mm_struct *mm
return handle_pte_fault(mm, vma, address, entry, pmd, flags, 0);
}
+int handle_speculative_fault(struct mm_struct *mm, unsigned long address,
+ unsigned int flags)
+{
+ pmd_t *pmd = NULL;
+ pte_t *pte, entry;
+ spinlock_t *ptl;
+ struct vm_area_struct *vma;
+ unsigned int seq;
+ int ret = VM_FAULT_RETRY;
+ int dead;
+
+ __set_current_state(TASK_RUNNING);
+ flags |= FAULT_FLAG_SPECULATIVE;
+
+ count_vm_event(PGFAULT);
+
+ rcu_read_lock();
+ if (!pte_map_lock(mm, NULL, address, pmd, flags, 0, &pte, &ptl))
+ goto out_unlock;
+
+ vma = find_vma(mm, address);
+
+ if (!vma)
+ goto out_unmap;
+
+ dead = RB_EMPTY_NODE(&vma->vm_rb);
+ seq = vma->vm_sequence.sequence;
+ /*
+ * Matches both the wmb in write_seqcount_begin/end() and
+ * the wmb in detach_vmas_to_be_unmapped()/__unlink_vma().
+ */
+ smp_rmb();
+ if (dead || seq & 1)
+ goto out_unmap;
+
+ if (!(vma->vm_end > address && vma->vm_start <= address))
+ goto out_unmap;
+
+ if (read_seqcount_retry(&vma->vm_sequence, seq))
+ goto out_unmap;
+
+ entry = *pte;
+
+ pte_unmap_unlock(pte, ptl);
+
+ ret = handle_pte_fault(mm, vma, address, entry, pmd, flags, seq);
+
+out_unlock:
+ rcu_read_unlock();
+ return ret;
+
+out_unmap:
+ pte_unmap_unlock(pte, ptl);
+ goto out_unlock;
+}
+
+
#ifndef __PAGETABLE_PUD_FOLDED
/*
* Allocate page upper directory.
Index: linux-2.6/include/linux/mm.h
===================================================================
--- linux-2.6.orig/include/linux/mm.h
+++ linux-2.6/include/linux/mm.h
@@ -829,6 +829,8 @@ int invalidate_inode_page(struct page *p
#ifdef CONFIG_MMU
extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long address, unsigned int flags);
+extern int handle_speculative_fault(struct mm_struct *mm,
+ unsigned long address, unsigned int flags);
#else
static inline int handle_mm_fault(struct mm_struct *mm,
struct vm_area_struct *vma, unsigned long address,
--
--
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next prev parent reply other threads:[~2010-01-04 20:49 UTC|newest]
Thread overview: 121+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-04 18:24 [RFC][PATCH 0/8] Speculative pagefault -v3 Peter Zijlstra
2010-01-04 18:24 ` [RFC][PATCH 1/8] mm: Remove pte reference from fault path Peter Zijlstra
2010-01-04 18:24 ` [RFC][PATCH 2/8] mm: Speculative pagefault infrastructure Peter Zijlstra
2010-01-04 18:24 ` [RFC][PATCH 3/8] mm: Add vma sequence count Peter Zijlstra
2010-01-04 18:24 ` [RFC][PATCH 4/8] mm: RCU free vmas Peter Zijlstra
2010-01-05 2:43 ` Paul E. McKenney
2010-01-05 8:28 ` Peter Zijlstra
2010-01-05 16:05 ` Paul E. McKenney
2010-01-04 18:24 ` [RFC][PATCH 5/8] mm: Speculative pte_map_lock() Peter Zijlstra
2010-01-04 18:24 ` Peter Zijlstra [this message]
2010-01-05 0:25 ` [RFC][PATCH 6/8] mm: handle_speculative_fault() KAMEZAWA Hiroyuki
2010-01-05 3:13 ` Linus Torvalds
2010-01-05 8:17 ` Peter Zijlstra
2010-01-05 8:57 ` Peter Zijlstra
2010-01-05 15:34 ` Linus Torvalds
2010-01-05 15:40 ` Al Viro
2010-01-05 16:10 ` Linus Torvalds
2010-01-06 15:41 ` Peter Zijlstra
2010-01-05 9:37 ` Peter Zijlstra
2010-01-05 23:35 ` Linus Torvalds
2010-01-05 4:29 ` Minchan Kim
2010-01-05 4:43 ` KAMEZAWA Hiroyuki
2010-01-05 5:10 ` Linus Torvalds
2010-01-05 5:30 ` KAMEZAWA Hiroyuki
2010-01-05 7:39 ` KAMEZAWA Hiroyuki
2010-01-05 15:26 ` Linus Torvalds
2010-01-05 16:14 ` Linus Torvalds
2010-01-05 17:25 ` Andi Kleen
2010-01-05 17:47 ` Christoph Lameter
2010-01-05 18:00 ` Andi Kleen
2010-01-05 17:55 ` Linus Torvalds
2010-01-05 18:13 ` Christoph Lameter
2010-01-05 18:25 ` Linus Torvalds
2010-01-05 18:46 ` Christoph Lameter
2010-01-05 18:56 ` Linus Torvalds
2010-01-05 19:15 ` Christoph Lameter
2010-01-05 19:28 ` Linus Torvalds
2010-01-05 18:55 ` Paul E. McKenney
2010-01-05 19:08 ` Linus Torvalds
2010-01-05 19:23 ` Paul E. McKenney
2010-01-05 20:29 ` Peter Zijlstra
2010-01-05 20:46 ` Linus Torvalds
2010-01-05 21:00 ` Linus Torvalds
2010-01-05 23:29 ` Paul E. McKenney
2010-01-06 0:22 ` KAMEZAWA Hiroyuki
2010-01-06 1:37 ` Linus Torvalds
2010-01-06 2:52 ` KAMEZAWA Hiroyuki
2010-01-06 3:27 ` Linus Torvalds
2010-01-06 3:56 ` KAMEZAWA Hiroyuki
2010-01-06 4:20 ` Linus Torvalds
2010-01-06 7:06 ` KAMEZAWA Hiroyuki
2010-01-06 7:49 ` Minchan Kim
2010-01-06 9:39 ` Linus Torvalds
2010-01-07 1:00 ` KAMEZAWA Hiroyuki
2010-01-08 16:53 ` Peter Zijlstra
2010-01-08 17:22 ` Linus Torvalds
2010-01-08 17:43 ` Christoph Lameter
2010-01-08 17:52 ` Linus Torvalds
2010-01-08 18:33 ` Christoph Lameter
2010-01-08 18:46 ` Andi Kleen
2010-01-08 18:56 ` Christoph Lameter
2010-01-08 19:10 ` Andi Kleen
2010-01-08 19:11 ` Linus Torvalds
2010-01-08 19:28 ` Andi Kleen
2010-01-08 19:39 ` Linus Torvalds
2010-01-08 19:42 ` Linus Torvalds
2010-01-08 21:36 ` Linus Torvalds
2010-01-08 21:46 ` Christoph Lameter
2010-01-08 22:43 ` Linus Torvalds
2010-01-08 22:43 ` Linus Torvalds
2010-01-09 14:47 ` Ed Tomlinson
2010-01-10 5:27 ` Nitin Gupta
2010-01-05 15:14 ` Christoph Lameter
2010-01-05 8:18 ` Peter Zijlstra
2010-01-05 6:00 ` Minchan Kim
2010-01-05 4:48 ` Linus Torvalds
2010-01-05 6:09 ` Minchan Kim
2010-01-05 6:09 ` KAMEZAWA Hiroyuki
2010-01-05 6:24 ` Minchan Kim
2010-01-05 8:35 ` Peter Zijlstra
2010-01-05 13:45 ` Arjan van de Ven
2010-01-05 14:15 ` Andi Kleen
2010-01-05 15:17 ` Christoph Lameter
2010-01-06 3:22 ` Arjan van de Ven
2010-01-07 16:11 ` Christoph Lameter
2010-01-07 16:19 ` Linus Torvalds
2010-01-07 16:31 ` Linus Torvalds
2010-01-07 16:34 ` Paul E. McKenney
2010-01-07 16:36 ` Christoph Lameter
2010-01-08 4:49 ` Arjan van de Ven
2010-01-08 5:00 ` Linus Torvalds
2010-01-08 15:51 ` Christoph Lameter
2010-01-09 15:55 ` Arjan van de Ven
2010-01-07 17:22 ` Peter Zijlstra
2010-01-07 17:36 ` Linus Torvalds
2010-01-07 17:49 ` Linus Torvalds
2010-01-07 18:00 ` Peter Zijlstra
2010-01-07 18:15 ` Linus Torvalds
2010-01-07 21:49 ` Peter Zijlstra
2010-01-07 18:44 ` Linus Torvalds
2010-01-07 19:20 ` Paul E. McKenney
2010-01-07 20:06 ` Linus Torvalds
2010-01-07 20:25 ` Paul E. McKenney
2010-01-07 19:24 ` Christoph Lameter
2010-01-07 20:08 ` Linus Torvalds
2010-01-07 20:13 ` Linus Torvalds
2010-01-07 21:44 ` Peter Zijlstra
2010-01-07 22:33 ` Linus Torvalds
2010-01-08 0:23 ` KAMEZAWA Hiroyuki
2010-01-08 0:25 ` KAMEZAWA Hiroyuki
2010-01-08 0:39 ` Linus Torvalds
2010-01-08 0:41 ` Linus Torvalds
2010-01-07 23:51 ` Rik van Riel
2010-01-04 18:24 ` [RFC][PATCH 7/8] mm,x86: speculative pagefault support Peter Zijlstra
2010-01-04 18:24 ` [RFC][PATCH 8/8] mm: Optimize pte_map_lock() Peter Zijlstra
2010-01-04 21:41 ` [RFC][PATCH 0/8] Speculative pagefault -v3 Rik van Riel
2010-01-04 21:46 ` Peter Zijlstra
2010-01-04 23:20 ` Rik van Riel
2010-01-04 21:59 ` Christoph Lameter
2010-01-05 0:28 ` KAMEZAWA Hiroyuki
2010-01-05 2:26 ` Minchan Kim
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