Re: [PATCH v3] IB/umem: Release pid in error and ODP flow

[Kenneth Lee <liguozhu@hisilicon.com>]

On Tue, Jan 03, 2017 at 12:12:24PM +0200, Leon Romanovsky wrote:
> Date: Tue, 3 Jan 2017 12:12:24 +0200
> From: Leon Romanovsky <leon@kernel.org>
> To: Kenneth Lee <liguozhu@hisilicon.com>
> CC: dledford@redhat.com, sean.hefty@intel.com, hal.rosenstock@gmail.com,
>  robin.murphy@arm.com, jroedel@suse.de, egtvedt@samfundet.no,
>  vgupta@synopsys.com, dave.hansen@linux.intel.com, lstoakes@gmail.com,
>  krzk@kernel.org, sebott@linux.vnet.ibm.com, markb@mellanox.com,
>  linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org
> Subject: Re: [PATCH v3] IB/umem: Release pid in error and ODP flow
> User-Agent: Mutt/1.7.2 (2016-11-26)
> Message-ID: <20170103101224.GH12077@mtr-leonro.local>
> 
> On Tue, Jan 03, 2017 at 10:32:50AM +0800, Kenneth Lee wrote:
> > On Sun, Jan 01, 2017 at 08:47:12AM +0200, Leon Romanovsky wrote:
> > > Date: Sun, 1 Jan 2017 08:47:12 +0200
> > > From: Leon Romanovsky <leon@kernel.org>
> > > To: Kenneth Lee <liguozhu@hisilicon.com>
> > > CC: dledford@redhat.com, sean.hefty@intel.com, hal.rosenstock@gmail.com,
> > >  robin.murphy@arm.com, jroedel@suse.de, egtvedt@samfundet.no,
> > >  vgupta@synopsys.com, dave.hansen@linux.intel.com, lstoakes@gmail.com,
> > >  krzk@kernel.org, sebott@linux.vnet.ibm.com, markb@mellanox.com,
> > >  linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org
> > > Subject: Re: [PATCH v3] IB/umem: Release pid in error and ODP flow
> > > User-Agent: Mutt/1.7.2 (2016-11-26)
> > > Message-ID: <20170101064712.GQ26885@mtr-leonro.local>
> > >
> > > On Fri, Dec 30, 2016 at 06:18:29PM +0800, Kenneth Lee wrote:
> > > > There are two bugfixes in this patch:
> > > >
> > > > Fixes: 87773dd56d54 ("IB: ib_umem_release() should decrement mm->pinned_vm from ib_umem_get")
> > > > 	This patch introduce the get_task_pid but not put it back on all error
> > > > 	path
> > > >
> > > > Fixes: 8ada2c1c0c1d ("IB/core: Add support for on demand paging regions")
> > > > 	This patch introduce a ODP flow without release pid before enter it
> > > >
> > > >
> > > > Signed-off-by: Kenneth Lee <liguozhu@hisilicon.com>
> > > > Reviewed-by: Haggai Eran <haggaie@mellanox.com>
> > > > ---
> > > > Change from v1 to v2:
> > > >   Correcting the patch title and description
> > > > Change from v2 to v3:
> > > >   Update the title and add "Fixes" fields in the description
> > >
> > > OK,
> > >
> > > I see that you still didn't read Documentation/SubmittingPatches. You
> > > must read that document before you are sending patches.
> > >
> > > But I'll stop here, the code is correct (it fixes bugs) and commit message
> > > more usefull than before.
> > >
> > >
> > > >
> > > >  drivers/infiniband/core/umem.c | 2 ++
> > > >  1 file changed, 2 insertions(+)
> > > >
> > > > diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
> > > > index 1e62a5f..4609b92 100644
> > > > --- a/drivers/infiniband/core/umem.c
> > > > +++ b/drivers/infiniband/core/umem.c
> > > > @@ -134,6 +134,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
> > > >  		 IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_MW_BIND));
> > > >
> > > >  	if (access & IB_ACCESS_ON_DEMAND) {
> > > > +		put_pid(umem->pid);
> > > >  		ret = ib_umem_odp_get(context, umem);
> > > >  		if (ret) {
> > > >  			kfree(umem);
> > > > @@ -149,6 +150,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
> > > >
> > > >  	page_list = (struct page **) __get_free_page(GFP_KERNEL);
> > > >  	if (!page_list) {
> > > > +		put_pid(umem->pid);
> > > >  		kfree(umem);
> > > >  		return ERR_PTR(-ENOMEM);
> > > >  	}
> > > > --
> > > > 1.9.1
> > > >
> > > > --
> > > > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
> > > > the body of a message to majordomo@vger.kernel.org
> > > > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >
> > Thanks,
> >
> > I did read the doc, but maybe I mis-understant some points. Could you please
> > point it out?
> 
> Fixes line should be placed above bottom signatures.
> 
> As an example of properly written patch, you can take a look on the
> following patch [1] from Steve.
> 
> [1] http://marc.info/?l=linux-rdma&m=148244272205411&w=2

Thank you. A sample help a lot.

But please allow me to argue a little:
Documentation/process/submitting-patches.rst does really not mention where Fixes
tags should be put:)

> 
> >
> > And sorry. please ignore the last message. I forget to use a bottom-post style.
> >
> >
> >
> > --
> > 			-Kenneth(Hisilicon)



-- 
			-Kenneth(Hisilicon)