[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20240125183639.585ec73f@kernel.org>
Date: Thu, 25 Jan 2024 18:36:39 -0800
From: Jakub Kicinski <kuba@...nel.org>
To: Stefan Wahren <wahrenst@....net>
Cc: "David S. Miller" <davem@...emloft.net>, Eric Dumazet
<edumazet@...gle.com>, Paolo Abeni <pabeni@...hat.com>, Lino Sanfilippo
<LinoSanfilippo@....de>, Florian Fainelli <f.fainelli@...il.com>,
netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH V3 01/14 next] qca_spi: Improve SPI thread creation
On Wed, 24 Jan 2024 23:31:58 +0100 Stefan Wahren wrote:
> The qca_spi driver create/stop the SPI kernel thread in case
> of netdev_open/close. This isn't optimal because there is no
> need for such an expensive operation.
>
> So improve this by moving create/stop of the SPI kernel into
> the init/uninit ops. The open/close ops could just
> 'park/unpark' the SPI kernel thread.
What's the concern? I don't think that creating a thread is all
expensive. And we shouldn't have a thread sitting around when
the interface isn't use. I mean - if you ask me what's better
a small chance that the creation will fail at open or having
a parked and unused thread when device is down - I'd pick
the former.. But I may well be missing the point.
> @@ -825,6 +813,7 @@ static int
> qcaspi_netdev_init(struct net_device *dev)
> {
> struct qcaspi *qca = netdev_priv(dev);
> + struct task_struct *thread;
>
> dev->mtu = QCAFRM_MAX_MTU;
> dev->type = ARPHRD_ETHER;
> @@ -848,6 +837,15 @@ qcaspi_netdev_init(struct net_device *dev)
> return -ENOBUFS;
> }
>
> + thread = kthread_create(qcaspi_spi_thread, qca, "%s", dev->name);
> + if (IS_ERR(thread)) {
> + netdev_err(dev, "%s: unable to start kernel thread.\n",
> + QCASPI_DRV_NAME);
> + return PTR_ERR(thread);
I'm 90% sure this leaks resources on failure, too.
Rest of the series LGTM!
Powered by blists - more mailing lists