From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f43.google.com (mail-pa0-f43.google.com [209.85.220.43]) by kanga.kvack.org (Postfix) with ESMTP id D7B0A6B0038 for ; Thu, 12 Nov 2015 02:15:10 -0500 (EST) Received: by padhx2 with SMTP id hx2so56519345pad.1 for ; Wed, 11 Nov 2015 23:15:10 -0800 (PST) Received: from mail-pa0-x235.google.com (mail-pa0-x235.google.com. [2607:f8b0:400e:c03::235]) by mx.google.com with ESMTPS id nn10si18094798pbc.131.2015.11.11.23.15.09 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 11 Nov 2015 23:15:10 -0800 (PST) Received: by pasz6 with SMTP id z6so58370510pas.2 for ; Wed, 11 Nov 2015 23:15:09 -0800 (PST) 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 Content-Transfer-Encoding: quoted-printable 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> Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" 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 Ok i will send a V3 patch. > On Nov 5, 2015, at 16:50, Kirill A. Shutemov = wrote: >=20 > 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); >>>=20 >>> maybe passing down pte instead of pfn? >>=20 >> 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. >=20 > Agreed. >=20 > --=20 > Kirill A. Shutemov -- 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