From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 2EFA1DDD2; Tue, 2 Sep 2025 09:03:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756803830; cv=none; b=M244URbpIsd4U0o1t3X8kAaJAMRBNLRsGXbC52+hDkWFeXSidVBotghwitolzmvSjhjpl4BAmphqnOe5qiZt0JE3cYb1wnUuAw62Nx80PrYSSl/nnVakKewGC6kGS++uv5kZrrjFpr5Z0eJJtNdxYhQo3Gz3rbctKXqCqt85D1g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756803830; c=relaxed/simple; bh=XSGx5WcjG6DtHmHu+mXlygkptZCaYu11n470dQLZtrI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=m9nUJuK8bmMJvRhPfFGMZwyKnrNDayazF/Qwocwlj/D3SMkUInVV+6nxj7pax9cUWsukL+iufAu0ogz0iv4NOUwI4pI47Drcj2H4tNUXNUR8m2jaPZfP/mVaeqnC+lgtNjMBDaufxnfKc6MeR+xSqx1cFr04dR1TpzTnnmFIcXw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pDoF4F1d; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="pDoF4F1d" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 783ACC4CEED; Tue, 2 Sep 2025 09:03:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756803829; bh=XSGx5WcjG6DtHmHu+mXlygkptZCaYu11n470dQLZtrI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pDoF4F1dlQJzNzeAOE+nPxgGph3Af8zNLZjnysoRvmJvJRZY7pHhSZNfABBhtFoEr OeFRyv1qr/XSOUtz+ujVBH30cibIlbPXwGvIRiqNKhyOjQKpTDKO9WMr2E1ferofKp LodSlw+81TM1NJhLGjMLb5CEO5v6tHSFBcEEAtGoyuzsnXEj2fX/a4AFdC/rszk6+p ho3khiUqUy2X87s+qoejMRaHNEkGEICVrWmBauy3LqdLRAlP4pP1rbUhV/TE44cYk8 MKSUnRAgObq5D8OYj0ndGEl38SjjRrsN3XcdHPOcvMEEJLi0xs4vdF9zTUWlHsvJMg Zh9Cj5r7FrPqg== Date: Tue, 2 Sep 2025 10:03:45 +0100 From: Simon Horman To: Jakub Kicinski Cc: davem@davemloft.net, netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch, ecree.xilinx@gmail.com, gal@nvidia.com, joe@dama.to, linux-kselftest@vger.kernel.org, shuah@kernel.org Subject: Re: [PATCH net-next v2 1/2] selftests: drv-net: rss_ctx: use Netlink for timed reconfig Message-ID: <20250902090345.GV15473@horms.kernel.org> References: <20250901173139.881070-1-kuba@kernel.org> Precedence: bulk X-Mailing-List: linux-kselftest@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: <20250901173139.881070-1-kuba@kernel.org> On Mon, Sep 01, 2025 at 10:31:38AM -0700, Jakub Kicinski wrote: > The rss_ctx test has gotten pretty flaky after I increased > the queue count in NIPA 2->3. Not 100% clear why. We get > a lot of failures in the rss_ctx.test_hitless_key_update case. > > Looking closer it appears that the failures are mostly due > to startup costs. I measured the following timing for ethtool -X: > - python cmd(shell=True) : 150-250msec > - python cmd(shell=False) : 50- 70msec > - timed in bash : 45- 55msec > - YNL Netlink call : 2- 4msec > - .set_rxfh callback : 1- 2msec > > The target in the test was set to 200msec. We were mostly measuring > ethtool startup cost it seems. Switch to YNL since it's 100x faster. > > Lower the pass criteria to 150msec, no real science behind this number > but we removed some overhead, drivers which previously passed 200msec > should easily pass 150msec now. > > Separately we should probably follow up on defaulting to shell=False, > when script doesn't explicitly ask for True, because the overhead > is rather significant. > > Switch from _rss_key_rand() to random.randbytes(), YNL takes a binary > array rather than array of ints. > > Signed-off-by: Jakub Kicinski > --- > v2: > - increase the threshold to safer 150msec > - mention change away from _rss_key_rand() > v1: https://lore.kernel.org/20250829220712.327920-1-kuba@kernel.org Reviewed-by: Simon Horman