From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.kdab.com (mail.kdab.com [176.9.126.58]) (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 D4A842BE02B for ; Wed, 10 Sep 2025 08:59:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=176.9.126.58 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757494797; cv=none; b=IhiI3nM7icFlQkTwvKzV5mg75mG07SeQUVrJAKl+7u+KaxoqVgaAA9+vqB8LHaP4F6a4FFjCycsZt/IjUFq975GRNFjat9MhUdmPGCc9Fqihs25u8B8VuJLIVeCvUqwfDVk8YX2GGcBoMAPCtTVzpzphaBXAs/Hl99AOeQysLig= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757494797; c=relaxed/simple; bh=opNS0WGEyO7j9MxtLjvROuwsO8mR/dhgOz2V732OluI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=CKhA+YUvFVyoo5ilQREvqelLvqTV+HYGWgnUUwon8HCOz7yrlh+9fiJydxHeTvh/hJdRNY8/e8uAHvHDEs8VcA87KA8MozfrLqb2rgLkH1EVW1JlzzTrv8QMUYajlLmdGHJVk+FCyKe9xeJfdhsOR5S5THJbTv1WcuXapD5sID4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=kdab.com; spf=pass smtp.mailfrom=kdab.com; dkim=pass (1024-bit key) header.d=kdab.com header.i=@kdab.com header.b=F2t87ajH; arc=none smtp.client-ip=176.9.126.58 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=kdab.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kdab.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=kdab.com header.i=@kdab.com header.b="F2t87ajH" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kdab.com; h= content-type:content-type:content-transfer-encoding:mime-version :organization:message-id:date:date:subject:subject:from:from; s= dkim; t=1757494292; x=1758358293; bh=WN3bWpnnbaUVyOnbPS9Mm81PtmN OsyPBnj06g4ZtD/E=; b=F2t87ajHBbb1D/aQQp4CdDgfn2HjFNUb/e4ce8p/vSq XF64nJm4ziV/S6e4I8iuhNxA4scoY0PDV/rWwO+pV+Q3vxC6vfN7q7YPOpFwEUD+ yNSR+z+bndEQRY5c5cEJLKGPtNLuKfM+Auabh1nUYzyxCsHf22bG0Wp3d9X0ZptY = X-Virus-Scanned: amavisd-new at kdab.com From: Milian Wolff To: linux-perf-users@vger.kernel.org Cc: Chun-Tse Shao , acme@kernel.org Subject: combined usage of `--aio -z` corrupts perf.data files - fallout from COMPRESSED2? Date: Wed, 10 Sep 2025 10:51:31 +0200 Message-ID: <38208379.DOZC079dcN@milian-workstation> Organization: KDAB Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Hey all, for some context, see https://github.com/KDAB/hotspot/issues/ 736#issuecomment-3273734660 The gist is the following: ``` $ perf record --call-graph dwarf -z --aio -- ls ... [ perf record: Captured and wrote 0.005 MB perf.data, compressed (original 0.101 MB, ratio is 28.747) ] $ perf script Couldn't decompress data 0x598 [0xe53]: failed to process type: 83 [Operation not permitted] ``` If you remove the explicit `--aio` while keeping compression via `-z` enabled, then the result file can be parsed. Enabling `--aio` but disabling `-z` also works as expected. My understanding so far was that `-z` implies `--aio`, and that there should be zero semantic difference between `-z` and `-z --aio`. But apparently this was a misunderstanding on my end. I suspect that the above issue is related to the recent addition of the COMPRESSED2 record type, since commands combining both of these flags used to work fine until very recently. Cheers -- Milian Wolff | milian.wolff@kdab.com | Senior Software Engineer KDAB (Deutschland) GmbH, a KDAB Group company Tel: +49-30-521325470 KDAB - Trusted Software Excellence