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=1794673152; b=HXkr7A2kYfH2ILNP8HsGrtcMHeloJVZkcNEuDax0GavJNfG1aUZsyNiBAHxiDoP5Fh6B 29cQbpqnN3+zHIdXFuTXk8mizuDnQD+KLlWQGdFVSS4vIbaOz05UiYG8pvPJAk1qXkb32 bnS+5Dx1Qv8P8yX43/DpmtHLzgrKTzZAMWT30RqVtGZjoP8FE/8Uo6R0wq2NvxjO0Erb2 atCIySy89rFmb71zOr7oV2hVq+KE7btb81x9HyGp1TYch0VtyFqbWtZ/+SPiSFhHCiy1A 7y3mWrIMMVx8fPY85/tERNXe48D8vvozkZNTCgnPK61MCBgLtI1Yz0uZVlLm27dJA6w== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794673152; h=Received:DKIM-Signature:Date:Message-ID:From:To:Cc:Subject: In-Reply-To:References:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=szGS1CeGbYGPkWuMoRnLaZZO05Fgspcv4JaKgVqioX8=; b=hXaVfH+LzSf4Uf0kKo5CVADBt5lOLGOGM+rYPBImTFhFvHa5AHm9INZpKYCyw68F4OZ9 MNO6osBoJ4T+ymKhOMfUOR8pSTYVLVAd+57GnHi6WqByhAudma9YZ2EJfqPAlBpTS/JgS 81n3wsr4xX0TU9szZJb3CGUYgfRzDEe1CO/iIoN81iIB+MKeT+VStR6POpAjeIS9ogDq2 k0fhO8ef6ZZ7l5Qys1F9gK73ZMcxHbNmaEuDqb+u2FkNDTpwttPfLdvBUGuKYt//9pG5f umQrYNp7eCFjzd/w1zCWNIAB+8J94+tZA4BKS3dxEJ6M2JZajoxBVFTSVoaoa1YDVuQ== 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=Jd12V7r+; 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 35350606A334; Sat, 14 Nov 2026 16:19:12 +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=Jd12V7r+ Received: by smtp.kernel.org (Postfix) with ESMTPSA id E1D811F000C4; Sat, 14 Nov 2026 16:19:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794673152; bh=szGS1CeGbYGPkWuMoRnLaZZO05Fgspcv4JaKgVqioX8=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=Jd12V7r+vrzapn2IZRbFJR/sbCR5TzTLJWCErWJDigzmgTMNu/l29Jb66myp5H/v2 ecp1DUFbBgvzJ2mLE7g1ouBu/4glAz4No0HFxfDRU3SyGw4QIBmk2T8YDeySpKS88x x35rMQ+HBMJRIi0l1EqP4twHkC5ttwo+wvRQOt07pLF4KR3//EEBdeubxiKyxdn+SG /nUMhMkBNRBDaIsGkgSTTjS3iK76rU/NYIZHpvYnhtQRc8sZf+ZXHKJ2N6NxX9g0jj kpGNoP9GT0dETMfuBbiIiLE8AKg0xAmTjBHD+QV2bfm8Ng07fF6r4FYz4SrvTy1QXS ZnvGBHME4+Xvw== Date: Sat, 14 Nov 2026 06:19:10 -1000 Message-ID: From: Tejun Heo To: Shakeel Butt Cc: bpf@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Kumar Kartikeya Dwivedi , Song Liu , Yonghong Song , John Fastabend , Jiri Olsa , Emil Tsalapatis , Ihor Solodrai , Roman Gushchin , Amery Hung , Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Meta kernel team , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH bpf-next 0/3] bpf, cgroup: Don't wait for cgroup_mutex to read or free cgroup bpf state In-Reply-To: <20261112172721.440275-1-shakeel.butt@linux.dev> References: <20261112172721.440275-1-shakeel.butt@linux.dev> X-Mailing-List: bpf@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit On Thu, Nov 12, 2026 at 09:27:12AM -0800, Shakeel Butt wrote: > In the Meta fleet, BPF_PROG_QUERY callers, link-info readers and the > cgroup bpf release work often wait minutes for cgroup_mutex. The holder is > almost always a cgroup mkdir or rmdir stuck on kernfs_rwsem. In one day, > hung-task reports showed this on 1,075 hosts (query), 94 hosts (link info) > and 458 hosts (release work). For the series, Acked-by: Tejun Heo Thanks. -- tejun