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=1794349344; b=iLYkneVR8mFvS8GBswJYsGcbhNyTpR1mTHOfQJrhQYvV6g6LVAb2fXcBWta5OBKZC9Z4 m//GnNSVqL9hujbT523ky+c0SuZQAvuHk2WrjDK52AN9UOvXJXlvWrbAjezMQUlnSXsUj GSRcNhDMrFuRXKaTPI1dk6aT1NcvhmajfIMcj7IQn+6TvqHUb/e+F4hiGo3X8oyYS7bgF zM+i3wbMfjgPq/O6Qd/ibFGwvAg4LuRbhPiRALjbW1CLO47AezPTorJFEsn3Gl4tbjZpL fEtyVx3rYMi2Xf9udEvm9iLFHbJn1f2Qy6LkXtMaAHvwyX0dB4xXwgXnaQVm+EdGgNg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794349344; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=oRN5HvO0CBqkuQMjGCiNB/lnQYVRw0AoGyghhRwfjYM=; b=LBKcbEE9S8D9ZFCv8LwO3gk6lo726zUwEUv9eB8w724S9Z1mm5rx+B4nLtW0IQoRE65Q LuklQ2S1+wvBSF2U6TinQGBsM7Yd6MDZ0sfOftqJk5ROf525VIRsQp02re9T0OXpLPETs zpkaCV07S1YlryrrrjGU5HmpPYd+C3HP/q+U+k/x1W/BDdDnuqYedvh0k4pehTlIOGmPx OL/L5GvdeFKbiDIdC+LvsoIgsHhgYfpSMDNgd6YHCBXH9rQbeb+etRbq2pLxHk/mAXe2O aCyVwlIpFXoUqA0OiIG8sPcLaUvusEXR/1lzU61wnX3oes3s9d2brbkMig45RRL+jNQ== 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=bxrLUMMr; 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 91212606A321 for ; Tue, 10 Nov 2026 22:22:24 +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=bxrLUMMr Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11FE31F008A2; Tue, 10 Nov 2026 22:22:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794349344; bh=oRN5HvO0CBqkuQMjGCiNB/lnQYVRw0AoGyghhRwfjYM=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=bxrLUMMrqY69KF5t6z3wTjv7xmTVqCn5Ik/ZcLTGwdCn+g/1iasiEFRlMwQVKAJP5 yiiKi6XrCioV26KKyeGC0q8K4JKyYEEFRUtjHUWBAUH2HIBeVhEk5nr7RoYbuFKI8p sN6m72YqwIPMxc0iv31tqBfvxa2TnNf0kxSGFr4D8IDx6FromvEafXBKxvMRe76Z1a WhcjQA5yE8xLv6TKOSZeyiAIjCUoZwla6WH5RtV8pUdcxz+Y7Y93OJsEUCfZDdh/uL hITv9/PpYO7Q5huLk1xm8gN8/td06WM/oA8Ff1kUBx9QvAar7O8seoM4recW2pNFpa c0G7aleiC+4lQ== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 02/20] perf machine: Protect machines->guests rbtree with a rw_semaphore Reply-To: sashiko-reviews@lists.linux.dev To: "Ian Rogers" Cc: linux-perf-users@vger.kernel.org In-Reply-To: <20261110220803.2503416-3-irogers@google.com> References: <20261027231513.816148-1-irogers@google.com> <20261110220803.2503416-1-irogers@google.com> <20261110220803.2503416-3-irogers@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 10 Nov 2026 22:22:23 +0000 X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > Unlike struct dsos, struct maps, and struct threads, struct machines had > no lock protecting its machines->guests rbtree. Synchronizing access to > machines->guests is needed both for concurrent guest machine lookups and > so machines__shrink() can safely iterate guest machines using > down_read_trylock(&machines->lock). >=20 > Add a rw_semaphore lock to struct machines to synchronize access to the > machines->guests rbtree across machines__add(), machines__find(), > machines__set_comm_exec(), machines__process_guests(), > machines__set_id_hdr_size(), machines__fprintf_dsos(), > machines__fprintf_dsos_buildid(), machines__destroy_kernel_maps(), and > machines__for_each_thread(), and check for an existing guest machine PID > under write lock in machines__add(). >=20 > Signed-off-by: Ian Rogers Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261110220803.2503= 416-1-irogers@google.com?part=3D2