Re: [PATCH] virtio_pci_modern: replace msleep(1) with usleep_range(1000, 2000)
From: Michael S. Tsirkin
Date: Mon Aug 17 2026 - 15:57:01 EST
On Mon, Aug 17, 2026 at 10:33:31PM +0530, Mirza Ishan Beg wrote:
> On Sun, Aug 16, 2026 at 05:38:06PM -0400, Michael S. Tsirkin wrote:
> > why do we care?
>
> Hi Michael,
>
> The motivation originally came from a checkpatch.pl warning, but looking directly at Documentation/timers/timers-howto.rst,
> there is a practical penalty here.
>
> The documentation explicitly notes for the 1-20ms range: "msleep(1~20) may not do what the caller intends, and will often sleep longer (~20 ms actual sleep for any value given in the 1~20ms range)."
>
> In these queue reset loops, using msleep(1) means each iteration may be extended to 10-20ms depending on HZ and timer slack. The document recommends using usleep_range() to avoid this overhead and provide the intended precision.
>
> Let me know if you'd like this explanation folded into a v2 commit message.
>
> --
> Mirza
I don't think we care anyway. We probably just want fsleep?