Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753450AbbKLHPM (ORCPT ); Thu, 12 Nov 2015 02:15:12 -0500 Received: from mail-pa0-f43.google.com ([209.85.220.43]:36828 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752997AbbKLHPK convert rfc822-to-8bit (ORCPT ); Thu, 12 Nov 2015 02:15:10 -0500 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 9.0 \(3094\)) Subject: Re: [PATCH V2] mm: fix kernel crash in khugepaged thread From: yalin wang In-Reply-To: <20151105085033.GB7614@node.shutemov.name> Date: Thu, 12 Nov 2015 15:15:01 +0800 Cc: Vlastimil Babka , Andrew Morton , "Kirill A. Shutemov" , jmarchan@redhat.com, mgorman@techsingularity.net, Ebru Akagunduz , willy@linux.intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8BIT Message-Id: <50393110-D4AD-4FAE-B3A6-63C2DE0730CC@gmail.com> References: <1445855960-28677-1-git-send-email-yalin.wang2010@gmail.com> <20151029003551.GB12018@node.shutemov.name> <563B0F72.5030908@suse.cz> <20151105085033.GB7614@node.shutemov.name> To: "Kirill A. Shutemov" X-Mailer: Apple Mail (2.3094) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1233 Lines: 33 Ok i will send a V3 patch. > On Nov 5, 2015, at 16:50, Kirill A. Shutemov wrote: > > On Thu, Nov 05, 2015 at 09:12:34AM +0100, Vlastimil Babka wrote: >> On 10/29/2015 01:35 AM, Kirill A. Shutemov wrote: >>>> @@ -2605,9 +2603,9 @@ out_unmap: >>>> /* collapse_huge_page will return with the mmap_sem released */ >>>> collapse_huge_page(mm, address, hpage, vma, node); >>>> } >>>> -out: >>>> - trace_mm_khugepaged_scan_pmd(mm, page_to_pfn(page), writable, referenced, >>>> - none_or_zero, result, unmapped); >>>> + trace_mm_khugepaged_scan_pmd(mm, pte_present(pteval) ? >>>> + pte_pfn(pteval) : -1, writable, referenced, >>>> + none_or_zero, result, unmapped); >>> >>> maybe passing down pte instead of pfn? >> >> Maybe just pass the page, and have tracepoint's fast assign check for !NULL and >> do page_to_pfn itself? That way the complexity and overhead is only in the >> tracepoint and when enabled. > > Agreed. > > -- > Kirill A. Shutemov -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/