Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756238Ab0G0LJL (ORCPT ); Tue, 27 Jul 2010 07:09:11 -0400 Received: from mail-wy0-f174.google.com ([74.125.82.174]:37038 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756173Ab0G0LJJ (ORCPT ); Tue, 27 Jul 2010 07:09:09 -0400 Date: Tue, 27 Jul 2010 12:09:04 +0100 From: Eric B Munson To: KOSAKI Motohiro Cc: akpm@linux-foundation.org, mingo@redhat.com, hugh.dickins@tiscali.co.uk, riel@redhat.com, peterz@infradead.org, anton@samba.org, hch@infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 1/2] Add trace points to mmap, munmap, and brk Message-ID: <20100727110904.GA6519@mgebm.net> References: <20100721223359.8710.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="YZ5djTAD1cGYuMQK" Content-Disposition: inline In-Reply-To: <20100721223359.8710.A69D9226@jp.fujitsu.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2160 Lines: 64 --YZ5djTAD1cGYuMQK Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, 21 Jul 2010, KOSAKI Motohiro wrote: > > This patch adds trace points to mmap, munmap, and brk that will report > > relevant addresses and sizes before each function exits successfully. > >=20 > > Signed-off-by: Eric B Munson >=20 > I don't think this is good idea. if you need syscall result, you should= =20 > use syscall tracer. IOW, This tracepoint bring zero information. >=20 > Please see perf_event_mmap() usage. Our kernel manage adress space by > vm_area_struct. we need to trace it if we need to know what kernel does. >=20 > Thanks. The syscall tracer does not give you the address and size of the mmaped are= as so this does provide information above simply tracing the enter/exit points for each call. perf_event_mmap does provide the information for mmap calls. Originally I = sent a patch to add a trace point to munmap and Peter Z asked for corresponding = points in the mmap family. If the consensus is that the trace point in munmap is = the only one that should be added I can resend that patch. --=20 Eric B Munson IBM Linux Technology Center ebmunson@us.ibm.com --YZ5djTAD1cGYuMQK Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iQEcBAEBAgAGBQJMTr5QAAoJEH65iIruGRnNmSgH/12U99EVo3kI42/mdzDVQsN7 HeA54RKgS49LefEaGRJrL5YcySn+OoEcKJHbqo5ci9bZ+E/NNAsQ3FLrJbKHkXSP fg6+8rGUmjXCxKRhV90A4kdV+njkv6zC50t5kwf++YVfAYKnlfoqRI8qMaGpkx3z hOsCbbYrIl1An6huj2RNf4JtpMyX72E4gEyt4SR7tYWlY3QvX+qKYyauFwSZLW8j MFh2IKZdPtn5mDJl+Lgtwx2485hWxte1sBlVKYYRcZUFuU0uirTedCjTLrZr6AHL F+0wliiphdh4GfuFEZwtBp8zPy77POk9RMUBtP86UkNQYsx7sKa/B3hm2/+c6D0= =+aKZ -----END PGP SIGNATURE----- --YZ5djTAD1cGYuMQK-- -- 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/