From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: <20070116101815.426856000@taijtu.programming.kicks-ass.net> References: <20070116094557.494892000@taijtu.programming.kicks-ass.net> Date: Tue, 16 Jan 2007 10:46:00 +0100 From: Peter Zijlstra Subject: [PATCH 3/9] mm: allow PF_MEMALLOC from softirq context Content-Disposition: inline; filename=PF_MEMALLOC-softirq.patch Sender: owner-linux-mm@kvack.org Return-Path: To: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-mm@kvack.org Cc: David Miller , Peter Zijlstra List-ID: 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 --- 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 -- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org