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=1794591193; b=02Wq9CKCKYECAzDUrkP6M99DyUmg1Pw52b2k0CsSaTpUjuFNzDj/MhP7DNzVpNtxdyVC nH1y8jmmNDZDFgZTuJzeGjLYFqsmMcS96lYPDEqjQq0FA+iSGeLFP+3/WER04lggSlU/E GkGxilg+g0K+2IsI7StU32wL0N0OIX9i8oO/7UN2x2ajUBd2DmK2BN2KEjAzPQM+5qtER x1gLQzH0RdxHmOalK5WgVEqsVxPL8FEHXqmB4qEdiRE3m42DI9kJevxEPor9/qO8FwFHV rIX/hdjlxwap75KsjFfttH5SvEiD0hhJr09haW+4MoSzWAKBUpkiTIr+2h/qjM8m5RA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794591193; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=zCMTdwXSL5D4rZBu5Nd6pLYm3zrQhiAcTbUFQwEz73Y=; b=4ui4OpfQo4aFOymKQ4mY2b9O3UHeELGttzZ2Ib9DqgYuVCZbSmTu4kHgw8dJ7affn7Qj nv88/fHsDjhjYkx5wifTjHKbNR0UMVc4jbg8K806skqogPVSOH4WJCnnwCW5McnQnz9gF s3i/eCamMv0ZfPCXQVq3fqQ687eLZBe3yBFqUg3i+NdiUe0TjUGkqrBIpexwXHCEzR9i4 D/SczrYypdc09p8WV/jKZhWTWLTGzNUKr+cmRSCpIKjbdrzKI4ewJwX3hP1ccA2zIYYdx KzTjstQBQXn7PCVnabgagBg/7UaBwHfAEku/a7Vu+dPE8YlSHwMAvt1cAWXz4RrnNJA== 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=PXUVgMJl; 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 0A9CB6075840 for ; Fri, 13 Nov 2026 17:33:13 +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=PXUVgMJl Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD4441F000C4; Fri, 13 Nov 2026 17:33:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794591192; bh=zCMTdwXSL5D4rZBu5Nd6pLYm3zrQhiAcTbUFQwEz73Y=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=PXUVgMJltsOmkvieB9Ifvt3mcjlFUmF61oTUQlOANBAO0HKVnyCBJFLeboMmuCngH jO+lc+2KahcFZb1wJLLjuYhcXhI+sGDZ/Nt0S8QYJ7ulLfwVNHWNxPTmbAwruJfnuN VyGdVAzE3ryE6Y+wF1B5pZ3FzxFvy81+Zevz1k7SROpxvg5g4KuAVKnwJamZ/zm3B/ j4g8/H9ilbIqaU+yeXfOPQtwpIn5NfHGtEJTEPb5axJbcwc/IYCbkW42A3kf2wzm81 FKkfm3VavMw/JQIBVrnrN996dCh34+5kwwKqUN1aCTq+fgGm0ie0C0hp8K4Y8hsfW7 1lMaVOtwVkP1Q== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v4 05/23] 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: <20261113171734.2188066-6-irogers@google.com> References: <20261110220803.2503416-1-irogers@google.com> <20261113171734.2188066-1-irogers@google.com> <20261113171734.2188066-6-irogers@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 13 Nov 2026 17:33:12 +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/20261113171734.2188= 066-1-irogers@google.com?part=3D5