From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D3CAB20C494; Tue, 4 Feb 2025 17:12:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738689130; cv=none; b=YSkHld5BuUOa5SJSSYN3ulJ1XUQEOq1HgzmoFC2sAxxWp7stTZMyi71WdMkrgQxNm1DhLKZgWpG4a9zLfgR9+YsSi+KYR8qUSXFmbvFg9jQ9XjmY64B3QRFC7JZ25MrVEsxcPQjHsPSUvB9tXDrPigU4vhVMNTnYJmXeyXIc/k4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738689130; c=relaxed/simple; bh=yNJVGDNkyLK6lOVSRR5EsvFcIsTNRYoR9X3o1HljH2E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qmOxYBdLUJT9vl5dzMCBoZEZMWbgnULti4PSCBjgfjTCWUAsWpObVkpkjGgxN7DCT9UedbW+6470CShULydsnbzgah4RI0ns0jcYSb8rWG1+GSt43wjMibzc6hWoggGRY9wxHmUw24Kgg2QaNwF2UFTWMnNVtOzOszVW+VM2qJU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nYPTYucN; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nYPTYucN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AEC4AC4CEDF; Tue, 4 Feb 2025 17:12:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1738689130; bh=yNJVGDNkyLK6lOVSRR5EsvFcIsTNRYoR9X3o1HljH2E=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nYPTYucNU13/7E1+heWjaa+BF29s/cOh2rZeO/wdC5Ez2TDv4Ww4a537I1kiW0QUQ fn/118Vh8b1DVUBYFju9KnxLxjW7/MyImsAf2ZG6F6AmkRsacNURYly/t2J7g1jY2N F9teiOddJjnVZBsriiPW2SxP1cF0k27zpG4cydyc= Date: Tue, 4 Feb 2025 18:12:07 +0100 From: Greg Kroah-Hartman To: Vince Weaver Cc: "Liang, Kan" , Alexander Shishkin , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Jiri Olsa , Ian Rogers , Adrian Hunter Subject: Re: [PATCH] perf/core: move all of the pmu devices into their own location Message-ID: <2025020447-gyration-wireless-f7da@gregkh> References: <2025020304-chip-trench-4e56@gregkh> <87pljyyx68.fsf@ubik.fi.intel.com> <2025020426-spool-refreeze-2870@gregkh> <2025020408-apron-fled-d29e@gregkh> <6edcf7f8-d496-524e-2250-49284dfb55e4@maine.edu> Precedence: bulk X-Mailing-List: linux-perf-users@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: <6edcf7f8-d496-524e-2250-49284dfb55e4@maine.edu> On Tue, Feb 04, 2025 at 11:41:38AM -0500, Vince Weaver wrote: > On Tue, 4 Feb 2025, Greg Kroah-Hartman wrote: > > > > > It seems that the majority of the perf code IS looking in the correct > > place, just mem-events.c seemed wrong. > > I hate to tell you, but other places in userspace are depending on the > current setup. libpfm4, used by PAPI, is looking directly in /sys/devices > for pmus and will break with the changes you are planning. Then that too needs to be fixed, sorry. Again, devices can, and will, move around in /sys/devices/ you can never hard-code any paths there. Any userspace code must ALWAYS be able to handle that, that's a sysfs requirement. And do you have a link to the source for that code? Good news is that if the code is fixed in userspace, it will work for any kernel (old or new). thanks, greg k-h