From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (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 0D22C3A6F17; Wed, 8 Jul 2026 15:26:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=82.195.75.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783524363; cv=none; b=aK9GXyoX+9i3EYdYb5TQ89oFsA65HI/nHhAX5TCVszcUPoMNsxoxTazUPF++KVoVoOLgeqJy4fwDwLm4C6Tdi5VDOhqrTIKxZfBh5G16tENXbLzIvLv8Ucnho7npgMRyXavNYfVgDOj5yFlAa787EjYAXkCzRPMq+4ogfwP/k8c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783524363; c=relaxed/simple; bh=odcECtMHFEoUn6zU4zviED276a4aIPGxcfNjbkl/W2I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cf7pIODjdJdb02ErX/m1AKtu7ZFE0Q9umGFPoDxckuMPq1nzAtQZhreQJY7bYy+iV2OEv59cToU+yDue2mPJTpphwkBkzyPPYbe3m/U2TtksUSZBWXm4rG+TJK6I4T0MJv2iEA6ckL0loWN2/HutRxz9fcs3DI7zNbJ+NJHYLIQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org; spf=pass smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=hBiuNXRz; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b="hBiuNXRz" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=odcECtMHFEoUn6zU4zviED276a4aIPGxcfNjbkl/W2I=; b=hBiuNXRz44gyJFpaWPuKfz6gri TnLPMnrqYk/DhyAjZ1aywdiQQlaIjzyWM0nq5FskuRqBV+eMyYt96hWOz+srAvJLOUmowTYXWY0YM 2sTCI1LgaBjRYwj7DrlLR5pQejUPmmsPkNBxmkwptZ515o0R40xmvukBnp+dlrqDSh6KTUcnc6TML o56dxX9k6naSnKKQgF5VoxqGTLWGmWtU4/0JWDh0goiV2D+QDihcBOgz7+rwbYApwobIspxKi1pFp affFbVAyb7eC/5W/Oc4XVdH4NQ12KGylJIGmeEZrwRVZ+lnZ6YP6piS5bMOr0OIZaeZq+Q2aXDepC GEPybpfQ==; Received: from authenticated-user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1whU9p-0032gh-2n; Wed, 08 Jul 2026 15:25:54 +0000 Date: Wed, 8 Jul 2026 08:25:48 -0700 From: Breno Leitao To: Usama Arif Cc: davem@davemloft.net, edumazet@google.com, horms@kernel.org, kuba@kernel.org, kuniyu@google.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, willemb@google.com, shakeel.butt@linux.dev, hannes@cmpxchg.org, riel@surriel.com, kernel-team@meta.com Subject: Re: [PATCH] net: use sync wakeups for socket error reports Message-ID: References: <20260708133815.3419465-1-usama.arif@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260708133815.3419465-1-usama.arif@linux.dev> X-Debian-User: leitao On Wed, Jul 08, 2026 at 06:38:15AM -0700, Usama Arif wrote: > Measured on a 176-core EPYC 9D64 host running a Meta production > workload, bpftrace on tracepoint:ipi:ipi_send_cpu with a kstack filter > attributed the sock_def_error_report -> ep_poll_callback -> > try_to_wake_up -> ttwu_queue_wakelist -> __smp_call_single_queue > chain to 16,326 IPIs/min. I am interested in why so many sock_def_error_report(). That's seems a lot for genuine socket errors (RST/ICMP) on a healthy host, so I suspect these aren't errors at all? Can you share the full stack above sock_def_error_report()?