From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH] iommu/amd: Use wait_event in put_pasid_state_wait Date: Wed, 4 Feb 2015 17:36:25 +0100 Message-ID: <20150204163625.GP3702@8bytes.org> References: <1423062622-28257-1-git-send-email-joro@8bytes.org> <20150204163450.GD5029@twins.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20150204163450.GD5029@twins.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org To: Peter Zijlstra Cc: iommu@lists.linux-foundation.org, Benjamin LaHaise , Jesse Barnes , linux-aio@kvack.org, linux-kernel@vger.kernel.org, Oded Gabbay , jroedel@suse.de List-Id: iommu@lists.linux-foundation.org On Wed, Feb 04, 2015 at 05:34:50PM +0100, Peter Zijlstra wrote: > On Wed, Feb 04, 2015 at 04:10:22PM +0100, Joerg Roedel wrote: > > From: Joerg Roedel > > > > Now that I learned about possible spurious wakeups this > > place needs fixing too. Replace the self-coded sleep variant > > with the generic wait_event() helper. > > > > Signed-off-by: Joerg Roedel > > --- > > drivers/iommu/amd_iommu_v2.c | 9 +-------- > > 1 file changed, 1 insertion(+), 8 deletions(-) > > > > diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c > > index b6398d7..5cc1409 100644 > > --- a/drivers/iommu/amd_iommu_v2.c > > +++ b/drivers/iommu/amd_iommu_v2.c > > @@ -266,14 +266,7 @@ static void put_pasid_state(struct pasid_state *pasid_state) > > > > static void put_pasid_state_wait(struct pasid_state *pasid_state) > > { > > - DEFINE_WAIT(wait); > > - > > - prepare_to_wait(&pasid_state->wq, &wait, TASK_UNINTERRUPTIBLE); > > - > > - if (!atomic_dec_and_test(&pasid_state->count)) > > - schedule(); > > - > > - finish_wait(&pasid_state->wq, &wait); > > + wait_event(pasid_state->wq, !atomic_read(&pasid_state->count)); > > free_pasid_state(pasid_state); > > } > > You just lost your atomic_dec. Right, thanks.