From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 09F27F9CB for ; Wed, 18 Jun 2025 14:45:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750257953; cv=none; b=R76Dzv8Uo0sp8EHajrrS9VhnpdLkfG63nSAKCvTRFYQKxa0mYAOWzz2waqVhRKS9Sv5G/a1IelF0IozyFnwgcZjcoCdbl8nby4NfRLMA9rJO0sqbE54pLB4/29ih50VTjW1i5wFPaX+O1O9GZB1vUwXzotu7/AJWW1P1eFe4O4c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750257953; c=relaxed/simple; bh=3PMenXLIAleTQFLPxN1TrTm7bTq0JqnHSJ2681Ke1qA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=f5mqTrFMFJJYEvo4hBfNI/hkAot1UNczYmqOA2ShC2RSLTPbQihx8GjgZDPbQ+Wo0v3TGeaCli+BnZYrHWuWYWQoLlZIFz46t3TSFbnZMsKiwmx0WUHt3DirSqS97nfgUtURMGfHhAxrz55yhogwzKyTG7tDBab+ihdYQEz0K/s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=LpqQRJKG; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="LpqQRJKG" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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; bh=CdQZ8qypEmHTOwhRReMpAgIHTzFIKXyL9o3uWNhSCCU=; b=LpqQRJKGBoLwjSMFGCA8rPt5aW d8zcyC8x70cdN/JYOAFDxAlXt8/T9t7ovVM3ymgWRCwohFVSalyPbAKL8sGqM/mfP6mGw2g444cmS ubHzQnpzEYeEGAFWlVSkcScgdU/noM5e4CuYoYQTxTZ4y+iOtlrvqWlAgvjtimfdFFWXDwlMd+wbo 0WEvCvx5fhm3mgyIFCoBCW2rUw/JRGCfkP58yohn8MEg0FTyn5cWRkDj5pph2LzadQVRY1VmFAsTL U2MV81oafVwz6YNTDdwDhwdM9NjhkhY1jCZjCnI65BZHTJnsObJfEasxXz1tuHg0q6kAVnuni+FeK UvIVJnsg==; Received: from 2001-1c00-8d82-d000-266e-96ff-fe07-7dcc.cable.dynamic.v6.ziggo.nl ([2001:1c00:8d82:d000:266e:96ff:fe07:7dcc] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1uRu2t-0000000473U-09ke; Wed, 18 Jun 2025 14:45:47 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 1F75E307FB7; Wed, 18 Jun 2025 16:45:45 +0200 (CEST) Date: Wed, 18 Jun 2025 16:45:45 +0200 From: Peter Zijlstra To: "Liang, Kan" Cc: Mark Rutland , "Mi, Dapeng" , mingo@redhat.com, acme@kernel.org, namhyung@kernel.org, tglx@linutronix.de, dave.hansen@linux.intel.com, irogers@google.com, adrian.hunter@intel.com, jolsa@kernel.org, alexander.shishkin@linux.intel.com, linux-kernel@vger.kernel.org, ak@linux.intel.com, zide.chen@intel.com, broonie@kernel.org Subject: Re: [RFC PATCH 06/12] perf: Support extension of sample_regs Message-ID: <20250618144545.GD1613200@noisy.programming.kicks-ass.net> References: <20250617133333.GU1613376@noisy.programming.kicks-ass.net> <20250617140617.GC1613633@noisy.programming.kicks-ass.net> <20250617144416.GY1613376@noisy.programming.kicks-ass.net> <20250618093500.GH1613376@noisy.programming.kicks-ass.net> <0782de41-c8c4-4077-8498-651fb9a10ef5@linux.intel.com> <20250618133003.GC1613200@noisy.programming.kicks-ass.net> <99087e26-192f-4fa6-b43b-0c6a39c45b38@linux.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <99087e26-192f-4fa6-b43b-0c6a39c45b38@linux.intel.com> On Wed, Jun 18, 2025 at 09:52:12AM -0400, Liang, Kan wrote: > I didn't know we have the alignment requirement for the output. Perf buffer is in u64 units. > If so, > > PERF_SAMPLE_SIMD_REGS := { > u64 vectors_mask; > u64 pred_mask; > u64 vector_length:16, > pred_length:16, > reserved:32; > u64 data[]; > } I really don't think we need this complication; XSAVE is a real pain in the arse, but I think we have enough bits in XSTATE_BV to tell what is what.