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From: David Miller <davem@davemloft.net>
To: bjorn.andersson@linaro.org
Cc: aneela@codeaurora.org, clew@codeaurora.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-msm@vger.kernel.org
Subject: Re: [PATCH v2 2/5] net: qrtr: Implement outgoing flow control
Date: Fri, 31 May 2019 14:46:35 -0700 (PDT)	[thread overview]
Message-ID: <20190531.144635.1962054387021988238.davem@davemloft.net> (raw)
In-Reply-To: <20190531011753.11840-3-bjorn.andersson@linaro.org>

From: Bjorn Andersson <bjorn.andersson@linaro.org>
Date: Thu, 30 May 2019 18:17:50 -0700

> +	flow = radix_tree_lookup(&node->qrtr_tx_flow, key);
> +	if (flow)
> +		atomic_set(&flow->pending, 0);

You can't just zero out an atomic counter without extra synchronization
which protects you from the increment paths.

And since you'll need a lock to cover all of those paths, you don't
need to use an atomic_t and instead can use a plain integer.

  reply	other threads:[~2019-05-31 21:46 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-31  1:17 [PATCH v2 0/5] QRTR flow control improvements Bjorn Andersson
2019-05-31  1:17 ` [PATCH v2 1/5] net: qrtr: Move resume-tx transmission to recvmsg Bjorn Andersson
2019-05-31  1:17 ` [PATCH v2 2/5] net: qrtr: Implement outgoing flow control Bjorn Andersson
2019-05-31 21:46   ` David Miller [this message]
2019-05-31  1:17 ` [PATCH v2 3/5] net: qrtr: Migrate node lookup tree to spinlock Bjorn Andersson
2019-05-31  1:17 ` [PATCH v2 4/5] net: qrtr: Make qrtr_port_lookup() use RCU Bjorn Andersson
2019-05-31  1:17 ` [PATCH v2 5/5] net: qrtr: Remove receive worker Bjorn Andersson

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