Re: [PATCH RFC v1 1/1] mtd_blkdevs: avoid soft lockups with some mtd/spi devices

[Richard Weinberger]

David,

----- Ursprüngliche Mail -----
> Von: "David Decotigny" <decot+git@xxxxxxxxxx>
> An: "linux-kernel" <linux-kernel@xxxxxxxxxxxxxxx>
> CC: "Miquel Raynal" <miquel.raynal@xxxxxxxxxxx>, "richard" <richard@xxxxxx>, "Vignesh Raghavendra" <vigneshr@xxxxxx>,
> "linux-mtd" <linux-mtd@xxxxxxxxxxxxxxxxxxx>, "David Decotigny" <ddecotig@xxxxxxxxxx>
> Gesendet: Mittwoch, 26. Januar 2022 09:57:35
> Betreff: [PATCH RFC v1 1/1] mtd_blkdevs: avoid soft lockups with some mtd/spi devices

> From: David Decotigny <ddecotig@xxxxxxxxxx>
> 
> With some spi devices, the heavy cpu usage due to polling the spi
> registers may lead to netdev timeouts, RCU complaints, etc. This can
> be acute in the absence of CONFIG_PREEMPT. This patch allows to give
> enough breathing room to avoid those false positives.

is the problem real or not? From your description it is not clear to me.
Please include lockdep splats and/or hung-task logs in the commit message.

I have no problem with adding a cond_resched() but first we need to
understand the issue a little better.

Thanks,
//richard