From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 12148 invoked by alias); 28 Mar 2018 21:42:07 -0000 Mailing-List: contact elfutils-devel-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Post: List-Help: List-Subscribe: Sender: elfutils-devel-owner@sourceware.org Received: (qmail 12049 invoked by uid 89); 28 Mar 2018 21:42:06 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Checked: by ClamAV 0.99.4 on sourceware.org X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.9 required=5.0 tests=AWL,BAYES_00,SPF_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy=H*r:MSK, 26pm, 26PM, H*i:sk:1522247 X-Spam-Status: No, score=-2.9 required=5.0 tests=AWL,BAYES_00,SPF_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on sourceware.org X-Spam-Level: X-HELO: vmicros1.altlinux.org Received: from vmicros1.altlinux.org (HELO vmicros1.altlinux.org) (194.107.17.57) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 28 Mar 2018 21:42:04 +0000 Received: from mua.local.altlinux.org (mua.local.altlinux.org [192.168.1.14]) by vmicros1.altlinux.org (Postfix) with ESMTP id 0256372D2CD for ; Thu, 29 Mar 2018 00:42:02 +0300 (MSK) Received: by mua.local.altlinux.org (Postfix, from userid 508) id E3AC87CC74C; Thu, 29 Mar 2018 00:42:01 +0300 (MSK) Date: Wed, 28 Mar 2018 21:42:00 -0000 From: "Dmitry V. Levin" To: elfutils-devel@sourceware.org Subject: Re: [PATCH] libdwfl: Use process_vm_readv when available. Message-ID: <20180328214201.GA18606@altlinux.org> Mail-Followup-To: elfutils-devel@sourceware.org References: <20180318004323.21340-1-mark@klomp.org> <20180320223202.GE6269@wildebeest.org> <1522247606.15770.68.camel@klomp.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="0F1p//8PRICkK4MW" Content-Disposition: inline In-Reply-To: <1522247606.15770.68.camel@klomp.org> X-IsSubscribed: yes X-SW-Source: 2018-q1/txt/msg00120.txt.bz2 --0F1p//8PRICkK4MW Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Content-length: 1057 On Wed, Mar 28, 2018 at 04:33:26PM +0200, Mark Wielaard wrote: > On Tue, 2018-03-20 at 23:32 +0100, Mark Wielaard wrote: > > On Sun, Mar 18, 2018 at 01:43:23AM +0100, Mark Wielaard wrote: > > > If possible use process_vm_readv to read 4K blocks instead of fetching > > > each word individually with ptrace. For unwinding this often means we > > > only have to do one process_vm_readv of the stack instead of dozens of > > > ptrace calls. There is one 4K cache per process, cleared whenever a > > > thread is detached. > >=20 > > It seems to work well, but the GCC undefined sanitizer > > (configure --enable-sanitize-undefined) found an issue in the > > run-backtrace-native-biarch.sh testcase (from x86_64 to i686) > > when reading unaligned data. To fix that don't assign to the > > Dwarf_Word directly when unaligned, but use memcpy (which gcc > > seems to inline). >=20 > I pushed this to master now. Adding some comments about the word size > being actually architecture defined even though we use a 64bit > Dwarf_Word everywhere. Thanks! --=20 ldv --0F1p//8PRICkK4MW Content-Type: application/pgp-signature; name="signature.asc" Content-length: 801 -----BEGIN PGP SIGNATURE----- iQIcBAEBCAAGBQJavAwpAAoJEAVFT+BVnCUIkp4P/RY1ku7xRES5aKhNflwm6Ik4 UOMW0XX0YGRkL59EA6eydIFn0i9Q6OOHPlLpz3fXgd1foE950YEKt8+INYD7b+7m HRFU/4CI6aYXv1eYahZtH1qhqulTWm+2dypirrKySteeZ+PleVcSjZOHfqPNOWdJ RbJuNsNeQpkkuXWeRg+pIlEa2l7LY5vAVz3mt1DQbYcryvSM1w4GnnWGlRSlKvut /NIxEOTvUBrhEFK49d4Prv/rVfz1a7aqNgWL30+CGguktzxHJZ56e/eodsX9u8CC UBaK/ABHS9qEpmieiQtgzBqDPRlwVKG/qOce79n4yUBUFJNKUv+yPc8R7NAbe+bT 1W4+Aoa0EKuu63naoZSFAqZSpVsFZVCd2R8S6qUCIS7tcHzRa6ld1ZSq1p2FtcOO Pu+/mDwwjY0pc79sE2PUss+aNwm3hUwqBzV7ipC2hGR8Zv7nysKEVm0iTmLkRmww 1/chljR26BsrTVlnaNCDciZgn8bYseLf2mf1vxiQhLDnedLHSkVjahRcC34wnvyF J8v1QPZVL5qMSvM/8QUgUSe68qU09C9y+C0pCI7eQkVIy4xNRiEplzvS5hVuL6oD 37EgCu06rrP3GI6wFOEOoMMbaRi0Y+SiLRmO5V0sQTnak5wpMhCKuFG3OC7FwBdI jBz4wmleDT9+H591ueRC =E79v -----END PGP SIGNATURE----- --0F1p//8PRICkK4MW--