Re: [PATCH v7 1/2] devcoredump: remove the useless gfp_t parameter in dev_coredumpv and dev_coredumpm

[duoming]

Hello,

On Mon, 22 Aug 2022 11:21:36 -0700 Brian Norris wrote:

> Hi,
> 
> On Thu, Aug 18, 2022 at 8:47 AM <duoming@xxxxxxxxxx> wrote:
> > On Thu, 18 Aug 2022 16:58:01 +0200 Greg KH wrote:
> > > No, that is not necessary.  Do the work now so that there is no flag day
> > > and you don't have to worry about new users, it will all "just work".
> >
> > Do you mean we should replace dev_set_name() in dev_coredumpm() to some other
> > functions that could work both in interrupt context and process context?
> 
> No.
> 
> I believe the suggestion is that rather than change the signature for
> dev_coredumpv() (which means everyone has to agree on the new
> signature on day 1), you should introduce a new API, like
> dev_coredumpv_noatomic() (I'm not good at naming [1]) with the
> signature you want, and then migrate users over. Once we have a
> release with no users of the old API, we drop it.
> 
> There are plenty of examples of the kernel community doing similar
> transitions. You can search around for examples, but a quick search of
> my own shows something like this:
> https://lwn.net/Articles/735887/
> (In particular, timer_setup() was introduced, and all setup_timer()
> users were migrated to it within a release or two.)
> 
> Brian
> 
> [1] Seriously, dev_coredumpv_noatomic() is not a name I want to see
> last very long. Maybe some other trivial modification? Examples:
> 
> dev_core_dumpv()
> dev_coredump_v()
> device_coredumpv()
> ...

Thank you very much for your timer and suggestions!

Best regards,
Duoming Zhou