From: Simon Horman <horms@kernel.org>
To: Mingming Cao <mmc@linux.ibm.com>
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
Date: Fri, 4 Jul 2025 18:19:25 +0100 [thread overview]
Message-ID: <20250704171925.GO41770@horms.kernel.org> (raw)
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 <mmc@linux.ibm.com>
> Reviewed by: Brian King <bjking1@linux.ibm.com>
> Reviewed by: Dave Marquardt <davemarq@linux.ibm.com>
Reviewed-by: Simon Horman <horms@kernel.org>
next prev parent reply other threads:[~2025-07-04 17:19 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-02 17:18 [PATCH v2 net-next 0/4] Fix/Improve queue stats and subcrq indirect handling Mingming Cao
2025-07-02 17:18 ` [PATCH v2 net-next 1/4] ibmvnic: Use atomic64_t for queue stats Mingming Cao
2025-07-02 17:18 ` [PATCH v2 net-next 2/4] ibmvnic: Fix hardcoded NUM_RX_STATS/NUM_TX_STATS with dynamic sizeof Mingming Cao
2025-07-04 17:14 ` Simon Horman
2025-07-02 17:18 ` [PATCH v2 net-next 3/4] ibmvnic: Use ndo_get_stats64 to fix inaccurate SAR reporting Mingming Cao
2025-07-04 17:19 ` Simon Horman [this message]
2025-07-02 17:18 ` [PATCH v2 net-next 4/4] ibmvnic: Make max subcrq indirect entries tunable via module param Mingming Cao
2025-07-04 17:05 ` Simon Horman
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