From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794750413; b=e1T0g0hNUsPLLCY++lQSJJ/u8LCZ1yTsc3R8LWcdSyKJNGkK5+3z68LiWsqppLZD4XQR /WUkTa8V+/Cfl/bUqBxK/NQXPz8DtUNkz+AaARYfdZVwwVfNyFfLN56cNJ/14nO1LyNgo CS/92gC0EhWz4JMYD5RbHaXctwNG7ixY/lE4IHLyAPZ6lClKlUtyxvunQ/u7MZiULNowq y6TqYGIOvIQCqfCkH61uZxrppQUhUntIq67fxWbYOcABKUuOOEq+wQ5ZvGDBYQekISUd2 4ioLOiMBHsEG0XzM+sMjD8OxJMhLEcelWzgng/5vJLc+4tMu4bqR9+e/LEzgJH8GkdA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794750413; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=HrmERiRhoUGgaXqecMFLrnZYHaaWVLq1l1MJtgH3Jzg=; b=a+BDltrSryetBpI35d748+g9gFDYEwiC7YYDkFkUtL+z6+x2GexyhPhgM5UmWgb9x7dM RvTb7i0AdOcfThxTpLSJ1NSrDB4L39nB8rTLWjYfrfSa+v/s2EgLW5OovXtuoXF7lD325 8jTWehb8akHzYGeb7QFN35IzWbhGbEvo7eod1y2Lbiae1KNK+gUop3ZaPI0TSAN/Cy1lB wce2WJiChhogyYimPOlgiWKkatheYVel6DJURjC2Ku2JWHURGQq5+yC5AL3P3VK4D4BTc 4KQ3HK0slS8Rj8H2BNYfDu6B1t8ReGUv3tQxYfG/tOcBhQ/QeXb/YZlJ8XqjoIp4vig== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=WUpQQI8l; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7F619606A31D for ; Sun, 15 Nov 2026 13:46:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=WUpQQI8l Received: by smtp.kernel.org (Postfix) with ESMTPSA id 059611F000C4; Sun, 15 Nov 2026 13:46:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794750413; bh=HrmERiRhoUGgaXqecMFLrnZYHaaWVLq1l1MJtgH3Jzg=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=WUpQQI8lRNVL9a0wElZMM5hqTlq8XBUNPCC0lken/7cCTeBNbhrAs6sV5vCulB011 KZVScpRy60zzBKveFQvXoLNnmIQ1OP9j+J84IUxzAHdYr7PVoPZacY3039RdexABd6 nesHfYS4RlYGiB+IpRbsjHo6j5Pu9DG9JVZArPAveFiiJ/RxBVdQmbBXkdBVsK08yx QVgIrDapGSgyTBR/HvEW1OLTV5fDki1xaSxwj2+P2gDEnjEDpDhjI35G01/iFPV+S0 HRrfY/SHKcH7R7Lfr4QwOMsuPRv3jmXW0N26zAJ7lmHs+241vbdEzS498FK+rq68aU mXZTPazuJlWWQ== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH 1/4] perf synthetic-events: Split oversized thread maps into records Reply-To: sashiko-reviews@lists.linux.dev To: "Leo Yan" Cc: linux-perf-users@vger.kernel.org In-Reply-To: <20261115-perf_fix_large_threads-v1-1-69c9b86b9ae5@arm.com> References: <20261115-perf_fix_large_threads-v1-0-69c9b86b9ae5@arm.com> <20261115-perf_fix_large_threads-v1-1-69c9b86b9ae5@arm.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sun, 15 Nov 2026 13:46:52 +0000 X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > PERF_RECORD_THREAD_MAP has a 16-bit header.size field. With 16 bytes of > fixed fields and 24 bytes per entry, a record can hold at most 2,729 > threads within the 65,535-byte size limit. >=20 > For larger maps, header.size overflows and no longer describes the > entries counted by nr, so readers reject the record. >=20 > Split larger maps into records that fit the size field. Set > PERF_RECORD_MISC_THREAD_MAP_MORE in header.misc when another record > follows, and clear it in the final record. Preserve entry order and the > existing encoding for maps that fit in one record, including empty maps. >=20 > Stop synthesis if allocation or the event callback fails. >=20 > Signed-off-by: Leo Yan Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261115-perf_fix_l= arge_threads-v1-0-69c9b86b9ae5@arm.com?part=3D1