From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753230Ab1JKLyF (ORCPT ); Tue, 11 Oct 2011 07:54:05 -0400 Received: from smtp.citrix.com ([66.165.176.89]:8424 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751316Ab1JKLyD (ORCPT ); Tue, 11 Oct 2011 07:54:03 -0400 X-IronPort-AV: E=Sophos;i="4.68,523,1312171200"; d="scan'208";a="18114349" From: David Vrabel To: linux-kernel@vger.kernel.org CC: Jens Axboe , David Vrabel Subject: [PATCH] block: initialize the bounce pool if high memory may be added later Date: Tue, 11 Oct 2011 12:53:38 +0100 Message-ID: <1318334018-3312-1-git-send-email-david.vrabel@citrix.com> X-Mailer: git-send-email 1.7.2.5 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org init_emergency_pool() does not create the page pool for bouncing block requests if the current count of high pages is zero. If high memory may be added later (either via memory hotplug or a balloon driver in a virtualized system) then a oops occurs if a request with a high page need bouncing because the pool does not exist. So, always create the pool if memory hotplug is enabled and change the test so it's valid even if all high pages are currently in the balloon (the balloon drivers adjust totalhigh_pages but not max_pfn). Signed-off-by: David Vrabel --- mm/bounce.c | 9 ++++----- 1 files changed, 4 insertions(+), 5 deletions(-) diff --git a/mm/bounce.c b/mm/bounce.c index 1481de6..434fb4f 100644 --- a/mm/bounce.c +++ b/mm/bounce.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include @@ -26,12 +27,10 @@ static mempool_t *page_pool, *isa_page_pool; #ifdef CONFIG_HIGHMEM static __init int init_emergency_pool(void) { - struct sysinfo i; - si_meminfo(&i); - si_swapinfo(&i); - - if (!i.totalhigh) +#ifndef CONFIG_MEMORY_HOTPLUG + if (max_pfn <= max_low_pfn) return 0; +#endif page_pool = mempool_create_page_pool(POOL_SIZE, 0); BUG_ON(!page_pool); -- 1.7.2.5