From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755308AbaGIJ1o (ORCPT ); Wed, 9 Jul 2014 05:27:44 -0400 Received: from casper.infradead.org ([85.118.1.10]:58402 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754663AbaGIJ1m (ORCPT ); Wed, 9 Jul 2014 05:27:42 -0400 Date: Wed, 9 Jul 2014 11:27:33 +0200 From: Peter Zijlstra To: kan.liang@intel.com Cc: andi@firstfloor.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH V4 1/2] perf ignore LBR and extra_regs. Message-ID: <20140709092733.GD9918@twins.programming.kicks-ass.net> References: <1404838181-3911-1-git-send-email-kan.liang@intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="5gxpn/Q6ypwruk0T" Content-Disposition: inline In-Reply-To: <1404838181-3911-1-git-send-email-kan.liang@intel.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --5gxpn/Q6ypwruk0T Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jul 08, 2014 at 09:49:40AM -0700, kan.liang@intel.com wrote: > --- a/arch/x86/kernel/cpu/perf_event.h > +++ b/arch/x86/kernel/cpu/perf_event.h > @@ -464,6 +464,12 @@ struct x86_pmu { > */ > struct extra_reg *extra_regs; > unsigned int er_flags; > + /* > + * EXTRA REG MSR can be accessed > + * The extra registers are completely unrelated to each other. > + * So it needs a flag for each extra register. > + */ > + bool extra_msr_access[EXTRA_REG_MAX]; > =20 > /* > * Intel host/guest support (KVM) # pahole -C extra_reg arch/x86/kernel/cpu/perf_event_intel.o struct extra_reg { unsigned int event; /* 0 4 */ unsigned int msr; /* 4 4 */ u64 config_mask; /* 8 8 */ u64 valid_mask; /* 16 8 */ int idx; /* 24 4 */ /* size: 32, cachelines: 1, members: 5 */ /* padding: 4 */ /* last cacheline: 32 bytes */ }; There's still 4 empty bytes at the tail of extra_reg itself; would it make sense to store the availability of the reg in there? After all; the place we use it (x86_pmu_extra_regs) already has the pointer to the structure. --5gxpn/Q6ypwruk0T Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTvQsFAAoJEHZH4aRLwOS66agQALVd6JbGx1wS33MHZvHTaiwY bsFglzSSd+NWDXLa4e5slUjRcEVIMj9cocOGZ3uqmVA7tBeSwwvpz0HCf6OCshTo bIctn5Zzh+FaeHkesTGpgO6lP+HDlnvf0ZbuGW2zJN1TTq3Q3PdchpvdhsBEUfDL Azr06GBH4/Vsp+5ZA5vB3Q8uiwWZ6LdzEDQCQ/FKh0fmOE9rsR5+9XZ26Yh21+oK pwPF6GdxtfK9EySfmXUvq/8VlnbMp8P8NHF2ibHAs69mAZQk4jWdyRArNSYILXgf etbF3I3BoRyK93sll6/WLjklUfJhZA9mqFGLF57XSfaKmw2cxwFwSA3XQvBAXxRa zZcbKJRZy4sabpgb9HN10tNP+dFx9HfYNBvt8u5QKgRmF9YUF+x9G5LNcw7eHshL SkcQhiMdDlLzuIea3rrrX4o4l51nD47UYMkRiJ1pn5rkBzLEb/zOCz4lwN++4Asr bDUs+pZWuNXBLu6YajHWqLv6VmDQePNUMK8EEF6MCekII7b4AsgIX8J1KJQH1nPp scjs1MjSJdvhM4rFu2eYp0pkUTBxdI6t0egOzZRJAlzqCaa0hoWtpZRMjP6/N5YC VHardwml5nfJ8Xx4PaMfmobhmB6CGcFyfd181kvkJbu2aZDL+nH92LCe8QZZ+y8X MbCIJeHSQUabMwiLSeXL =Xo5M -----END PGP SIGNATURE----- --5gxpn/Q6ypwruk0T--