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From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-mm@kvack.org
Cc: David Miller <davem@davemloft.net>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: [PATCH 3/9] mm: allow PF_MEMALLOC from softirq context
Date: Tue, 16 Jan 2007 10:46:00 +0100	[thread overview]
Message-ID: <20070116101815.426856000@taijtu.programming.kicks-ass.net> (raw)
In-Reply-To: <20070116094557.494892000@taijtu.programming.kicks-ass.net>

[-- Attachment #1: PF_MEMALLOC-softirq.patch --]
[-- Type: text/plain, Size: 2119 bytes --]

Allow PF_MEMALLOC to be set in softirq context. When running softirqs from
a borrowed context save current->flags, ksoftirqd will have its own 
task_struct.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
 kernel/softirq.c |    3 +++
 mm/internal.h    |   14 ++++++++------
 2 files changed, 11 insertions(+), 6 deletions(-)

Index: linux-2.6-git/mm/internal.h
===================================================================
--- linux-2.6-git.orig/mm/internal.h	2006-12-14 10:02:52.000000000 +0100
+++ linux-2.6-git/mm/internal.h	2006-12-14 10:10:09.000000000 +0100
@@ -75,9 +75,10 @@ static int inline gfp_to_alloc_flags(gfp
 		alloc_flags |= ALLOC_HARDER;
 
 	if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
-		if (!in_interrupt() &&
-		    ((p->flags & PF_MEMALLOC) ||
-		     unlikely(test_thread_flag(TIF_MEMDIE))))
+		if (!in_irq() && (p->flags & PF_MEMALLOC))
+			alloc_flags |= ALLOC_NO_WATERMARKS;
+		else if (!in_interrupt() &&
+				unlikely(test_thread_flag(TIF_MEMDIE)))
 			alloc_flags |= ALLOC_NO_WATERMARKS;
 	}
 
@@ -117,9 +118,10 @@ static inline int gfp_to_rank(gfp_t gfp_
 	 */
 
 	if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
-		if (!in_interrupt() &&
-		    ((current->flags & PF_MEMALLOC) ||
-		     unlikely(test_thread_flag(TIF_MEMDIE))))
+		if (!in_irq() && (current->flags & PF_MEMALLOC))
+			return 0;
+		else if (!in_interrupt() &&
+				unlikely(test_thread_flag(TIF_MEMDIE)))
 			return 0;
 	}
 
Index: linux-2.6-git/kernel/softirq.c
===================================================================
--- linux-2.6-git.orig/kernel/softirq.c	2006-12-14 10:02:18.000000000 +0100
+++ linux-2.6-git/kernel/softirq.c	2006-12-14 10:02:52.000000000 +0100
@@ -209,6 +209,8 @@ asmlinkage void __do_softirq(void)
 	__u32 pending;
 	int max_restart = MAX_SOFTIRQ_RESTART;
 	int cpu;
+	unsigned long pflags = current->flags;
+	current->flags &= ~PF_MEMALLOC;
 
 	pending = local_softirq_pending();
 	account_system_vtime(current);
@@ -247,6 +249,7 @@ restart:
 
 	account_system_vtime(current);
 	_local_bh_enable();
+	current->flags = pflags;
 }
 
 #ifndef __ARCH_HAS_DO_SOFTIRQ

-- 


  parent reply	other threads:[~2007-01-16 10:28 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-16  9:45 [PATCH 0/9] VM deadlock avoidance -v10 Peter Zijlstra
2007-01-16  9:45 ` [PATCH 1/9] mm: page allocation rank Peter Zijlstra
2007-01-16  9:45 ` [PATCH 2/9] mm: slab allocation fairness Peter Zijlstra
2007-01-16  9:46 ` Peter Zijlstra [this message]
2007-01-16  9:46 ` [PATCH 4/9] mm: serialize access to min_free_kbytes Peter Zijlstra
2007-01-16  9:46 ` [PATCH 5/9] mm: emergency pool Peter Zijlstra
2007-01-16  9:46 ` [PATCH 6/9] mm: __GFP_EMERGENCY Peter Zijlstra
2007-01-16  9:46 ` [PATCH 7/9] mm: allow mempool to fall back to memalloc reserves Peter Zijlstra
2007-01-16  9:46 ` [PATCH 8/9] slab: kmem_cache_objs_to_pages() Peter Zijlstra
2007-01-16  9:46 ` [PATCH 9/9] net: vm deadlock avoidance core Peter Zijlstra
2007-01-16 13:25   ` Evgeniy Polyakov
2007-01-16 13:47     ` Peter Zijlstra
2007-01-16 15:33       ` Evgeniy Polyakov
2007-01-16 16:08         ` Peter Zijlstra
2007-01-17  4:54           ` Evgeniy Polyakov
2007-01-17  9:07             ` Peter Zijlstra
2007-01-18 10:41               ` Evgeniy Polyakov
2007-01-18 12:18                 ` Peter Zijlstra
2007-01-18 13:58                   ` Possible ways of dealing with OOM conditions Evgeniy Polyakov
2007-01-18 15:10                     ` Peter Zijlstra
2007-01-18 15:50                       ` Evgeniy Polyakov
2007-01-18 17:31                         ` Peter Zijlstra
2007-01-18 18:34                           ` Evgeniy Polyakov
2007-01-19 12:53                             ` Peter Zijlstra
2007-01-19 22:56                               ` Evgeniy Polyakov
2007-01-20 22:36                                 ` Rik van Riel
2007-01-21  1:46                                   ` Evgeniy Polyakov
2007-01-21  2:14                                     ` Evgeniy Polyakov
2007-01-21 16:30                                     ` Rik van Riel
2007-01-19 17:54                           ` Christoph Lameter
2007-01-17  9:12 ` [PATCH 0/9] VM deadlock avoidance -v10 Pavel Machek
2007-01-17  9:20   ` Peter Zijlstra

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