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 BE2E410F1; Sat, 25 May 2024 02:02:19 +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=1716602539; cv=none; b=KD1oAp0p+vQA6czVZff0lfrSa3T1Agx749UQScZ/CI3GsEwyVEsiqKkRrg0yBmd4QRNIqA1X4A+RlA7iMEUkSuGSW3QNoO7OfzDmAt5i9XPVQtbBADnPaMyEBHIvu7TR0sIO6W31uZOHFl+QxJ/FsaZv2eNoVBTEG49vH4yaBkE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716602539; c=relaxed/simple; bh=5gBj23WR+Jd5PBLCgdy1m6u3CMtsWTjfSjiNwSZ9C0g=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=WrJ/FnCiaicflQBd+6TI4cFi5Qe5DGznVZv8jR5PoOCYX5xgmTPkU3RXa9hYc5DkG10aUu5SG+fXRUIvRKFYTjz9oCuaZLPvMmErcQ5BEMLbl0XirV2DRcM8wCTbXvwk+6EjDL/NxGbv1mWTBi3hJBGT8hXEszL9tFd0gspP2jQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FUIREH4D; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FUIREH4D" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A09C4C2BBFC; Sat, 25 May 2024 02:02:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716602539; bh=5gBj23WR+Jd5PBLCgdy1m6u3CMtsWTjfSjiNwSZ9C0g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FUIREH4DDOYYHcp7rw98E+sFaj6AAT6aBzKJSkAUvpl2cE8uinGJKAtrjFbrts82a NIpNVC1AikZ3p102MCoTxiMrZ9rQ3atjMrSsn4BJT+wZLOU/6cWyK+ymeazhwtoEgO 0A5e7HSslM5EwXGeVqJKbINCedK//F4PFFr3teVHzQiyr/O+lwC/ZEdRG96tEDjWNn /9tPH47x5RFLLGK/Kks/9n6ZZQUHQGp7nm1xTUy726VbxC2+wMYpTYK3Tz9TPnlKqK Mg8uqpW8zcIYtzkudlh0rfYlBL8Qntt1xu4hjBMmHaqY1b+FwF83NQFHGFNFKFia81 7h6MY5LhKbyHA== Date: Fri, 24 May 2024 23:02:15 -0300 From: Arnaldo Carvalho de Melo To: Linus Torvalds Cc: Leo Yan , Mark Rutland , Ian Rogers , Ingo Molnar , Thomas Gleixner , Jiri Olsa , Namhyung Kim , Adrian Hunter , Clark Williams , Kate Carcia , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Anne Macedo , Bhaskar Chowdhury , Ethan Adams , James Clark , Kan Liang , Thomas Richter , Tycho Andersen , Yang Jihong Subject: Re: [GIT PULL] perf tools changes for v6.10 Message-ID: References: <20240521192614.3937942-1-acme@kernel.org> 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: On Fri, May 24, 2024 at 10:55:11PM -0300, Arnaldo Carvalho de Melo wrote: > On Fri, May 24, 2024 at 06:31:52PM -0700, Linus Torvalds wrote: > > On Tue, 21 May 2024 at 12:26, Arnaldo Carvalho de Melo wrote: > > > > > > perf tools fixes and improvements for v6.10: > > > > This actually broke 'perf' completely for me on arm64. > > > > With a 6.9 version of 'perf', I can do this: > > > > perf record -e cycles:pp make -j199 > > > > and it all works fine. > > > > With the current -git version, when I do the same, I instead get > > > > Error: > > cycles:pp: PMU Hardware doesn't support > > sampling/overflow-interrupts. Try 'perf stat' > > > > and after trying desperately to chase down what went wrong on the > > kernel side, I finally figured out that it wasn't a kernel change at > > all, it was the tooling that had changed. > > > > I did a 'git bisect', and it says > > > > 617824a7f0f73e4de325cf8add58e55b28c12493 is the first bad commit > > commit 617824a7f0f73e4de325cf8add58e55b28c12493 > > Author: Ian Rogers > > Date: Mon Apr 15 23:15:25 2024 -0700 > > > > perf parse-events: Prefer sysfs/JSON hardware events over legacy > > > > and very clearly this does *NOT* work at all for me. > > > > I didn't notice until now, simply because I had been busy with the > > merge window, so I hadn't been doing any profiles, but the merge > > window is calming down and the end is nigh, and I just wasted more > > time than I care to admit trying to figure out what went wrong in the > > kernel. > > > > And no, I don't speak JSON, and I have *no* idea what the legacy > > events are. Plus I'm not very familiar with the arm64 profiling etc > > anyway, so I'm just a clueless user here. > > > > I *can* confirm that just reverting that commit makes that trivial > > "perf record" work for me. So the bisect was good, and it reverts > > cleanly, but I don't know _why_ my arm64 setup hates it so much. > That is a good data point, we probably could go with the revert, but I > think Ian submitted a few patches fixing this issue that came up close > to LSFMM/BPF and the merge window, so didn't have time to sit on > linux-next for a while, I'm looking those up now. Couldn't find it quickly, its late here, perhaps Ian can chime in and point those fixes here. I'll try and continue tomorrow. - Arnaldo > ARM64 eyes on this would also be good. Adding Mark Rutland and Leo Yan > to the CC list, maybe they can help us here with the best course of > action.