RE: [PATCH v7 11/15] scsi: fnic: Modify fnic interfaces to use FDLS

From: Karan Tilak Kumar (kartilak)
Date: Fri Jan 10 2025 - 04:37:29 EST


On Thursday, January 9, 2025 12:24 AM, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
>
> On Wed, Jan 08, 2025 at 09:40:48PM +0000, Karan Tilak Kumar (kartilak) wrote:
> > On Tuesday, January 7, 2025 5:18 AM, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
> > > > @@ -1236,8 +1286,10 @@ static void __exit fnic_cleanup_module(void)
> > > > {
> > > > pci_unregister_driver(&fnic_driver);
> > > > destroy_workqueue(fnic_event_queue);
> > > > - if (fnic_fip_queue)
> > > > + if (fnic_fip_queue) {
> > > > + flush_workqueue(fnic_fip_queue);
> > > > destroy_workqueue(fnic_fip_queue);
> > >
> > > I don't think this change is necessary or related. But if it is then it
> > > needs to be split into its own patch with a Fixes tag.
> >
> > Thanks Dan.
> > We believe it is necessary to flush the frames in the fip queue before cleaning up.
> > We would like to keep this as it is.
>
> The issue with the patch is that it should have been split up into
> probably five separate small patches. Each change needs to be considered
> on its own and explained why it's required. This flush_workqueue()
> change wasn't even mentioned in the commit message at all. I don't blame
> *you* for that because you didn't know but someone should have told you.
>
> With regards to flush_workqueue(), I have looked some more today and the
> flush_workqueue() is not required so this chunk does not need to be
> backported to -stable kernels. But if it had been required, there is no
> way we could have done that with it all mixed together with other
> changes.
>
> I think there is a tool out somewhere which complains about code like
> this because I've seen a lot of patches removing the extra call to
> flush_workqueue().
>
> 97d26ae764a4 ("bcache: remove unnecessary flush_workqueue")
> fb4b9685779f ("EDAC/wq: Remove unneeded flush_workqueue()")
> d81c7cdd7a6d ("net/tls: Remove redundant workqueue flush before destroy")
> etc..
>
> regards,
> dan carpenter
>

Thanks for those references, Dan. Appreciate you taking the time to dig them up.
The Cisco team will review this information.

Regards,
Karan