From: Oliver Neukum <oneukum@suse.com>
To: Greg KH <greg@kroah.com>, Matthew Wilcox <willy@infradead.org>
Cc: linux-usb@vger.kernel.org
Subject: [2/4] cdc-acm: Convert acm_minors to XArray
Date: Tue, 19 Mar 2019 13:41:16 +0100 [thread overview]
Message-ID: <1552999276.14757.45.camel@suse.com> (raw)
On Di, 2019-03-19 at 13:14 +0100, Greg KH wrote:
> On Mon, Mar 18, 2019 at 02:17:11PM -0700, Matthew Wilcox wrote:
> > Signed-off-by: Matthew Wilcox <willy@infradead.org>
[..]
> > static int acm_alloc_minor(struct acm *acm)
> > {
> > - int minor;
> > -
> > - mutex_lock(&acm_minors_lock);
> > - minor = idr_alloc(&acm_minors, acm, 0, ACM_TTY_MINORS, GFP_KERNEL);
> > - mutex_unlock(&acm_minors_lock);
> > -
> > - return minor;
> > + return xa_alloc(&acm_minors, &acm->minor, acm,
> > + XA_LIMIT(0, ACM_TTY_MINORS - 1), GFP_KERNEL);
>
> So, the only thing "better" here is that you don't need a lock anymore?
Once this is accepted I can reduce the locking to a per instance
spinlock. But to start with a straight conversion is best.
Regards
Oliver
next reply other threads:[~2019-03-19 12:41 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-19 12:41 Oliver Neukum [this message]
-- strict thread matches above, loose matches on Subject: below --
2019-03-19 13:29 [2/4] cdc-acm: Convert acm_minors to XArray Matthew Wilcox
2019-03-19 12:39 Oliver Neukum
2019-03-19 12:14 Greg KH
2019-03-18 21:17 Matthew Wilcox
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