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 D50FA2E3707 for ; Fri, 4 Jul 2025 17:19:29 +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=1751649569; cv=none; b=kHf6e35DO93o+LpgGRgV82MMgsofLtAIWtIMHMKfJMCeLGL5QBQrc5L8w6sJ7TUeD1SZmpQmfC8cWAA70OM8YDoT/kJGSuiRAIhLdD20WLAf6Fp/JP/DXofXoelsF5daXksTONzZXG1QO/2bCbZ4P08mOVjzI1VSL7H54RI3ZZg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751649569; c=relaxed/simple; bh=63eeHKTGY7iDPjf5kDa47PI5nqnQJNjObDFdFYAyPY4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ehUCKwOU6I6iF0lMS94rGn1dEyMwAd9P+dAEVEResS2ssSLld0kvHNo3JnhhdyJu44rAXsD8xizqPfhoD3tpRPjBw/mIAtClSzEEmKvwvtQX23gsrWsMvgA4Fdeuz/JxeGlWDsW8wkRsC0DqkTpC7dzdCUfHSgVJMnDl00CBwL4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=caOz5lzb; 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="caOz5lzb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B92B0C4CEE3; Fri, 4 Jul 2025 17:19:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1751649569; bh=63eeHKTGY7iDPjf5kDa47PI5nqnQJNjObDFdFYAyPY4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=caOz5lzbh21dptuhdp0QAJsAqyJQThH3ru0FhNfYYw/VsJ73lXjSOVrmnXEJVBFgG kn3ZFc0S/4XTsPDZdmst/RBMyWZ1k+GctfTkQp+SSuf57RdpJGX5Y1KB1zz3eCD07q vY3oVCq25huqTemoUyVoYSq7O4CKhqnSgXnjkPOLoUwp/jOOCbxYXdkeABPlJ00j8U IDS0bCF7yChOGnA+fDDCzv3c2oxqQRjdN5Xwhn8fRqo+mN96m5Bp9T+h3nhowupF7R n67b/J65zD52C/pinnXwESe7r4de7LBnuEw8VKiTz6vpi47SDXweHtVYHj41iwnlnz zWBFQ6ugD9mPw== Date: Fri, 4 Jul 2025 18:19:25 +0100 From: Simon Horman To: Mingming Cao Cc: netdev@vger.kernel.org, bjking1@linux.ibm.com, haren@linux.ibm.com, ricklind@linux.ibm.com, davemarq@linux.ibm.com Subject: Re: [PATCH v2 net-next 3/4] ibmvnic: Use ndo_get_stats64 to fix inaccurate SAR reporting Message-ID: <20250704171925.GO41770@horms.kernel.org> References: <20250702171804.86422-1-mmc@linux.ibm.com> <20250702171804.86422-4-mmc@linux.ibm.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: <20250702171804.86422-4-mmc@linux.ibm.com> On Wed, Jul 02, 2025 at 10:18:03AM -0700, Mingming Cao wrote: > VNIC testing on multi-core Power systems showed SAR stats drift > and packet rate inconsistencies under load. > > Implements ndo_get_stats64 to provide safe aggregation of queue-level > atomic64 counters into rtnl_link_stats64 for use by tools like 'ip -s', > 'ifconfig', and 'sar'. Switch to ndo_get_stats64 to align SAR reporting > with the standard kernel interface for retrieving netdev stats. > > This removes redundant per-adapter stat updates, reduces overhead, > eliminates cacheline bouncing from hot path updates, and improves > the accuracy of reported packet rates. > > Signed-off-by: Mingming Cao > Reviewed by: Brian King > Reviewed by: Dave Marquardt Reviewed-by: Simon Horman