From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Lameter Subject: [12/17] Virtual Compound page allocation from interrupt context. Date: Tue, 18 Sep 2007 20:36:17 -0700 Message-ID: <20070919033643.073962340@sgi.com> References: <20070919033605.785839297@sgi.com> Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org To: Christoph Hellwig , Mel Gorman Return-path: Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:53636 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752050AbXISDgn (ORCPT ); Tue, 18 Sep 2007 23:36:43 -0400 Cc: David Chinner , Jens Axboe Content-Disposition: inline; filename=vcompound_interrupt_alloc Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org In an interrupt context we cannot wait for the vmlist_lock in __get_vm_area_node(). So use a trylock instead. If the trylock fails then the atomic allocation will fail and subsequently be retried. This only works because the flush_cache_vunmap in use for allocation is never performing any IPIs in contrast to flush_tlb_... in use for freeing. Signed-off-by: Christoph Lameter --- mm/vmalloc.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) Index: linux-2.6/mm/vmalloc.c =================================================================== --- linux-2.6.orig/mm/vmalloc.c 2007-09-18 10:52:11.000000000 -0700 +++ linux-2.6/mm/vmalloc.c 2007-09-18 10:54:21.000000000 -0700 @@ -289,7 +289,6 @@ static struct vm_struct *__get_vm_area_n unsigned long align = 1; unsigned long addr; - BUG_ON(in_interrupt()); if (flags & VM_IOREMAP) { int bit = fls(size); @@ -314,7 +313,14 @@ static struct vm_struct *__get_vm_area_n */ size += PAGE_SIZE; - write_lock(&vmlist_lock); + if (gfp_mask & __GFP_WAIT) + write_lock(&vmlist_lock); + else { + if (!write_trylock(&vmlist_lock)) { + kfree(area); + return NULL; + } + } for (p = &vmlist; (tmp = *p) != NULL ;p = &tmp->next) { if ((unsigned long)tmp->addr < addr) { if((unsigned long)tmp->addr + tmp->size >= addr) --