From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 3B38350C2B8 for ; Wed, 16 Sep 2026 14:41:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789569692; cv=none; b=f8IVQl/F9eRRXmB4P/CA9gQEsQ4fvAQYXOnCpu8apQtDB3N4cF/E00ApaMdwacgO5ua3VQhsQGjMWu4yrNkDuF1VDG203XNo8psvswKcjEOV0DELbdYMi6srywzCXlBHK/caVd1+mwnCfRus4uUnak80+x/sFvE50yeSQkqndrQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789569692; c=relaxed/simple; bh=mjqfdTowP5r3irrt1LbGxpiTstxT+W8ZjVF4sU+bepk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Hc8TcVMmDuWKlyxQrZrSblOXgllt1rVr4z8e+E/BwwuDrdpULQ000Xhz6ZLPQ9SAaGcAGWK1mGw4iEv32xbfxXEd4RNUQ57V0QyvCyOWbHCSoYmbfaVjm2bNx0FJnGxZT/wHEjf5A8M59fSvLAfKqsRX6IVYVjkPBEjGT6ES4lE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WKXghM7y; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WKXghM7y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E33FD1F000FF; Wed, 16 Sep 2026 14:41:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789569689; bh=82sCX0TvTRzwmUtFpBAYs8yegtSun3AYeBn0vabgQE8=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=WKXghM7yA4vICpye4shwC3xDWVWYBes52zArD8yKuEWlIbNMB+oUPA5/BkUotObvW 61qnzLhyMbG8jt5NiBK62i/Efwfg1yQFhjfDXZ9445IapfoJGWeqlj0LnkYgvI/ECo +cyx5E6RaoWLqB6+vcIpaH9Z5ehWthv9iloNPFBzDSUJEfLWmk52q4Vfkhz4TvPE3+ Okg9P+sk2MI/rCLnrmq5BXLpWa35YOHecY2zeQNLGL+6Polx+qJ0dLDMh42aXzhDJV JcQ7UACePlkuIiOv7eUIDK6EGBHuuIqUVI9uMeKqiukiJDW3CENOt1klARIAyhtl6Y 8dvqDb01ZeBMw== Date: Wed, 16 Sep 2026 15:41:24 +0100 From: Simon Horman To: Aleksandr Loktionov Cc: intel-wired-lan@lists.osuosl.org, anthony.l.nguyen@intel.com, netdev@vger.kernel.org Subject: Re: [PATCH iwl-next 1/4] ixgbe: lower IXGBE_ITR_ADAPTIVE_MAX_USECS to prevent RX starvation Message-ID: <20260916144124.GM51261@horms.kernel.org> References: <20260915125538.3975870-1-aleksandr.loktionov@intel.com> <20260915125538.3975870-2-aleksandr.loktionov@intel.com> Precedence: bulk X-Mailing-List: netdev@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: <20260915125538.3975870-2-aleksandr.loktionov@intel.com> On Tue, Sep 15, 2026 at 02:55:35PM +0200, Aleksandr Loktionov wrote: > From: Alexander Duyck > > At the current maximum of 126 us the minimum bulk-mode interrupt rate > is ~7936 interrupts/s. Under sustained full-line-rate bulk RX traffic > this is low enough that descriptor ring starvation can occur before the > next interrupt fires. > > Lower IXGBE_ITR_ADAPTIVE_MAX_USECS from 126 to 84 us. This raises the > minimum rate to ~11905 interrupts/s (~12K ints/s), providing enough > headroom to drain the ring before it wraps. > > Signed-off-by: Alexander Duyck > Signed-off-by: Aleksandr Loktionov Reviewed-by: Simon Horman