From mboxrd@z Thu Jan 1 00:00:00 1970 From: Qiang Yu Subject: Re: linux-next: build failure after merge of the drm-misc tree Date: Tue, 2 Apr 2019 21:56:08 +0800 Message-ID: References: <20190402105006.48f93e53@canb.auug.org.au> <20190402112656.GE22763@bombadil.infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <20190402112656.GE22763@bombadil.infradead.org> Sender: linux-kernel-owner@vger.kernel.org To: Matthew Wilcox Cc: Stephen Rothwell , Daniel Vetter , Intel Graphics , DRI , Linux Next Mailing List , Linux Kernel Mailing List , Eric Anholt List-Id: linux-next.vger.kernel.org On Tue, Apr 2, 2019 at 7:26 PM Matthew Wilcox wrote: > > On Tue, Apr 02, 2019 at 01:55:03PM +0800, Qiang Yu wrote: > > Thanks, patch is: > > Reviewed-by: Qiang Yu > > This looks like a fairly naive conversion from the old IDR API to the > XArray API. You should be able to remove mgr->lock entirely, relying on > the xa_lock for synchronising free and get. I'm afraid the a little complex free path may involve some might sleep functions so use a mutex lock instead of spinlock. > If you think it's worth it, > you could even use kfree_rcu() to free the ctx and kref_get_unless_zero() > and then your get path would be lock-free. I can take a look this way, thanks.