From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELuSiY+9RI1c8fKGN1twMPCX0f8UBJwX3XhmOBHOCtbOsqhUVyrxROCVY0RNPiLUZ5iqhaHx ARC-Seal: i=1; a=rsa-sha256; t=1521483698; cv=none; d=google.com; s=arc-20160816; b=vEgaI4akbY/a6uP2c7J1OMfNBsk1gGwbtH+gkkNd8zjUoJcN7aY2OGJtzS+ARvy6uW sIgMy1B4HQA+rXEGP9ePDw8jNZ2xgAGJitDtreTsoRNE/DNAIYj/2hLBBh63Mchp0mWS uSJH7flzjor1/obKqG5xbYyIaVQQl+vwB9ogtp5+rKP80OHHYaJwZ2QEZuwGxXX+plkJ Wq/DYq+ASwbLkEDAAFYfQx/iM9NaPEfV425vQ+N54NKTlJ989YHHJrQKoAS7LPEG1pml B6yiS/Fg5bFzh9XB+w5zqUnEpSBcNTHB0vDk7+eyRN3mCXNDvjDYc+NYFOskK9mvvjrL UVnA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=Gv5uNCfuSpIm8ZTExakhATehXXsuld+lUP4QTKvXSKo=; b=Op1BtcvM/pp8uyWCNXtNgz7FVw2nqubEK9IhUIp/t6lk739s6o2JoUVtujcoaAfCT0 vj2dXOIDCxGK6rR++k4OP+0a68MWXoAGyqfSV/WnT4onayzHyH2x09Ynaz6olIRg48Sb pUi8/oJJp1X55bfpX9lg2k02Xn/7NdE6KaHTjhKljKDbULZwz088X8DD0Kve/Fm9rL87 nORHfP9i7Qm1rY6HVpHno0fepYfV0N+N8pvsWbrzvJeCUSzd7YapYIN31uxHEnzy/2iK +6PMePtf0vjtuxcIUi3X+LXA3mCOaYBbPAJFZljAyAIW3njCjrOfIqt4KtVGkS4fbWV9 NyNg== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , "David S. Miller" , Sasha Levin Subject: [PATCH 4.9 084/241] bonding: refine bond_fold_stats() wrap detection Date: Mon, 19 Mar 2018 19:05:49 +0100 Message-Id: <20180319180754.675387089@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180319180751.172155436@linuxfoundation.org> References: <20180319180751.172155436@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1595390874214479458?= X-GMAIL-MSGID: =?utf-8?q?1595391290327686570?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 142c6594acbcc32391af9c15f8cd65c6c177698f ] Some device drivers reset their stats at down/up events, possibly fooling bonding stats, since they operate with relative deltas. It is nearly not possible to fix drivers, since some of them compute the tx/rx counters based on per rx/tx queue stats, and the queues can be reconfigured (ethtool -L) between the down/up sequence. Lets avoid accumulating 'negative' values that render bonding stats useless. It is better to lose small deltas, assuming the bonding stats are fetched at a reasonable frequency. Fixes: 5f0c5f73e5ef ("bonding: make global bonding stats more reliable") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/net/bonding/bond_main.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -3331,12 +3331,17 @@ static void bond_fold_stats(struct rtnl_ for (i = 0; i < sizeof(*_res) / sizeof(u64); i++) { u64 nv = new[i]; u64 ov = old[i]; + s64 delta = nv - ov; /* detects if this particular field is 32bit only */ if (((nv | ov) >> 32) == 0) - res[i] += (u32)nv - (u32)ov; - else - res[i] += nv - ov; + delta = (s64)(s32)((u32)nv - (u32)ov); + + /* filter anomalies, some drivers reset their stats + * at down/up events. + */ + if (delta > 0) + res[i] += delta; } }