Re: [PATCH] Revert "seqlock: lockdep assert non-preemptibility on seqcount_t write"

From: Sebastian Andrzej Siewior
Date: Wed Aug 19 2020 - 03:11:19 EST


On 2020-08-18 17:56:49 [-0700], Guenter Roeck wrote:
> Nice catch. FWIW, there is no obvious reason why this would need to be atomic.
> The calling code does not set a lock, meaning there can be two (or more)
> callers entering this code. Weird, especially since the code looks like it
> would actually need a mutex to work correctly. It might be interesting to
> see what happens if there are, say, half a dozen scripts/processes trying
> to read the hwmon attribute introduced by this patch at the same time.

=> https://lkml.kernel.org/r/20200818161439.3dkf6jzp3vuwmvvh@xxxxxxxxxxxxx

> Guenter

Sebastian