From: Jakub Kicinski <kuba@kernel.org>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Matthew Wilcox <willy@infradead.org>,
netdev@vger.kernel.org
Subject: Re: [PATCH 9/9] u64_stat: Remove the obsolete fetch_irq() variants
Date: Mon, 22 Aug 2022 11:05:43 -0700 [thread overview]
Message-ID: <20220822110543.4f1a8962@kernel.org> (raw)
In-Reply-To: <YwOd7Ex7W21WzQ8N@linutronix.de>
On Mon, 22 Aug 2022 17:17:00 +0200 Sebastian Andrzej Siewior wrote:
> Using u64_stats_fetch_begin() is most likely wrong in networking because
> the stats are updated while packets are received which is either in IRQ
> or in BH (except maybe for the SPI/I2C ethernet driver). The _bh()
> version was replaced with _irq() for netpoll reasons.
> u64_stats_fetch_begin() does not disable any of those two (IRQ, BH) on
> 32bit-UP and does not use a seqcount so it is possible that an update
> happens during the read out of stats. Let me look…
> drivers/net/ethernet/cortina/gemini.c
> reads in net_device_ops::ndo_get_stats64(), updates in NAPI.
>
> drivers/net/ethernet/huawei/hinic/hinic_rx.c
> reads in net_device_ops::ndo_get_stats64() and
> ethtool_ops::get_ethtool_stats(), updates in NAPI. Good.
>
> So I guess these want be fixed properly instead of silently via the
> series?
Guess so, but it shouldn't be extra work if we're delaying the driver
conversion till 6.1?
next prev parent reply other threads:[~2022-08-22 18:05 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20220817162703.728679-1-bigeasy@linutronix.de>
2022-08-17 16:27 ` [PATCH 8/9] u64_stats: Streamline the implementation Sebastian Andrzej Siewior
2022-08-17 16:27 ` [PATCH 9/9] u64_stat: Remove the obsolete fetch_irq() variants Sebastian Andrzej Siewior
2022-08-17 18:27 ` Jakub Kicinski
2022-08-18 15:27 ` Sebastian Andrzej Siewior
2022-08-18 16:02 ` Jakub Kicinski
2022-08-18 16:59 ` Sebastian Andrzej Siewior
2022-08-18 17:45 ` Jakub Kicinski
2022-08-22 15:17 ` Sebastian Andrzej Siewior
2022-08-22 18:05 ` Jakub Kicinski [this message]
2022-08-25 16:45 ` Sebastian Andrzej Siewior
2022-08-25 17:30 ` Jakub Kicinski
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