From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [PATCH v4 10/13] x86: perf/core: use PERF_PMU_CAP_NO_EXCLUDE for exclude incapable PMUs Date: Tue, 8 Jan 2019 11:48:41 +0100 Message-ID: <20190108104841.GD6808@hirez.programming.kicks-ass.net> References: <1546878450-20341-1-git-send-email-andrew.murray@arm.com> <1546878450-20341-11-git-send-email-andrew.murray@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=UhfLYtBVV0BYHzjXA1lV7ddvf6DHC5pz2MUBcrfYLSc=; b=oDFh5R9wWqZ2mX h3Gvp52iXf/ui4hH0zhMmfCgSGbfcShcQ9HhTslgsx92pc1bl90W4uM55l4BlC4FFqBlftl3Y3nYR 2Lrzstmr1+umlcb5aHiJW0dZhCyBOgafYMplX/FcCpsh1HahTwhHblJP7WBn1ColmjEZamYnn6Czx 2GEOns/y+SEpCMoC1EExkIBawpl4rnBIXjpxR5VLebivgzqQps0UrHhoh5NB0r4QjDIac6vmeD+jB siLJM2FE8RiFjLiRQqKNWRb/K0xdasuoMP4dT8+MHBgQTdoxUurfCk4wbE0+IN2qovZKSYY7fhQ+F ndjiJ1TdXOK0tXa3/GLA==; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=yTdZfVFtLBOKoGnllbQfxLoeT4ufqAHc7DRrU9MkNQI=; b=D+blUeSMEt5iyYRsyD647qCqA E4knXkY9NIqGXrAOJJ7U3Tp/S5G9sfNIelyVDRKA/lLBXsdM7L55vm0goMwBNElderAuuaR0OzxbW KOzeaQdPrg33fAHIAPCIVxMrFGSlJ6Sw4+QkDcEE7cloG/9bGoVNBrEKojKIcSWMojQ9L9AMqHjTD YUNuWzi5MlVZOVVgx7sflt+EFJ86eV2Zs4ziMehCGSWfRuHba+Vlz2szTpEgFD4b9t6kTeQOGPEd9 bC0dGYsRf1RclLpky5AqDZb6wUQIq4vcY/7D22MrRxB2Hk81kVOcYG2DvsVuobPkRCAy1j8zjr/c9 xUjXrMFAg==; Content-Disposition: inline In-Reply-To: <1546878450-20341-11-git-send-email-andrew.murray@arm.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Andrew Murray Cc: Mark Rutland , Benjamin Herrenschmidt , Will Deacon , Paul Mackerras , Shawn Guo , boris.ostrovsky@oracle.com, Michael Ellerman , x86@kernel.org, Russell King , Ingo Molnar , Matt Turner , suzuki.poulose@arm.com, Sascha Hauer , Arnaldo Carvalho de Melo , Ivan Kokshaysky , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Richard Henderson , jgross@suse.com, robin.murphy@arm.com, linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, Borislav Petkov , linuxppc-dev@lists.ozlabs.org On Mon, Jan 07, 2019 at 04:27:27PM +0000, Andrew Murray wrote: > For drivers that do not support context exclusion let's advertise the > PERF_PMU_CAP_NOEXCLUDE capability. This ensures that perf will > prevent us from handling events where any exclusion flags are set. > Let's also remove the now unnecessary check for exclusion flags. > > Signed-off-by: Andrew Murray > --- > arch/x86/events/amd/ibs.c | 13 +------------ > arch/x86/events/amd/power.c | 10 ++-------- > arch/x86/events/intel/cstate.c | 12 +++--------- > arch/x86/events/intel/rapl.c | 9 ++------- > arch/x86/events/intel/uncore_snb.c | 9 ++------- > arch/x86/events/msr.c | 10 ++-------- > 6 files changed, 12 insertions(+), 51 deletions(-) You (correctly) don't add CAP_NO_EXCLUDE to the main x86 pmu code, but then you also don't check if it handles all the various exclude options correctly/consistently. Now; I must admit that that is a bit of a maze, but I think we can at least add exclude_idle and exclude_hv fails in there, nothing uses those afaict. On the various exclude options; they are as follows (IIUC): - exclude_guest: we're a HV/host-kernel and we don't want the counter to run when we run a guest context. - exclude_host: we're a HV/host-kernel and we don't want the counter to run when we run in host context. - exclude_hv: we're a guest and don't want the counter to run in HV context. Now, KVM always implies exclude_hv afaict (for guests), I'm not sure what, if anything Xen does on x86 (IIRC Brendan Gregg once said perf works on Xen) -- nor quite sure who to ask, Boris, Jeurgen?