From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id C1F4A6B004D for ; Wed, 28 Oct 2009 13:53:58 -0400 (EDT) Subject: [PATCH 0/2] Some fixes to debug_kmap_atomic() From: Soeren Sandmann Date: 28 Oct 2009 18:53:55 +0100 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: mingo@elte.hu, a.p.zijlstra@chello.nl List-ID: Hi, Here are two patches that fix an issue with debug_kmap_atomic(). The first one is a pretty straightforward fix for a race that can cause an underflow, which in turn causes the stream of warnings to never end. The second patch extends debug_kmap_atomic() to deal with KM_IRQ_PTE, KM_NMI, and KM_NMI_PTE. I was seeing this because the __get_user_pages_fast() in arch/x86/kernel/cpu/perf_events.c ends up eventually calling kmap_atomic() with KM_PTE, which, with CONFIG_HIGHPTE enabled, ends up expanding to: #define __KM_PTE \ (in_nmi() ? KM_NMI_PTE : \ in_irq() ? KM_IRQ_PTE : \ KM_PTE0) and those KM_* types are not handled For the second patch, I am basically pattern matching, so I might be completely wrong. Thanks, Soren -- 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