From: John Hubbard <jhubbard@nvidia.com> To: ira.weiny@intel.com, Andrew Morton <akpm@linux-foundation.org> Cc: Jason Gunthorpe <jgg@ziepe.ca>, Dan Williams <dan.j.williams@intel.com>, Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>, Theodore Ts'o <tytso@mit.edu>, Michal Hocko <mhocko@suse.com>, Dave Chinner <david@fromorbit.com>, linux-xfs@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-ext4@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC PATCH v2 15/19] mm/gup: Introduce vaddr_pin_pages() Date: Fri, 9 Aug 2019 17:09:54 -0700 [thread overview] Message-ID: <6ed26a08-4371-9dc1-09eb-7b8a4689d93b@nvidia.com> (raw) In-Reply-To: <20190809225833.6657-16-ira.weiny@intel.com> On 8/9/19 3:58 PM, ira.weiny@intel.com wrote: > From: Ira Weiny <ira.weiny@intel.com> > > The addition of FOLL_LONGTERM has taken on additional meaning for CMA > pages. > > In addition subsystems such as RDMA require new information to be passed > to the GUP interface to track file owning information. As such a simple > FOLL_LONGTERM flag is no longer sufficient for these users to pin pages. > > Introduce a new GUP like call which takes the newly introduced vaddr_pin > information. Failure to pass the vaddr_pin object back to a vaddr_put* > call will result in a failure if pins were created on files during the > pin operation. > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > --- > Changes from list: > Change to vaddr_put_pages_dirty_lock > Change to vaddr_unpin_pages_dirty_lock > > include/linux/mm.h | 5 ++++ > mm/gup.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 64 insertions(+) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 657c947bda49..90c5802866df 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1603,6 +1603,11 @@ int account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc); > int __account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc, > struct task_struct *task, bool bypass_rlim); > > +long vaddr_pin_pages(unsigned long addr, unsigned long nr_pages, > + unsigned int gup_flags, struct page **pages, > + struct vaddr_pin *vaddr_pin); > +void vaddr_unpin_pages_dirty_lock(struct page **pages, unsigned long nr_pages, > + struct vaddr_pin *vaddr_pin, bool make_dirty); Hi Ira, OK, the API seems fine to me, anyway. :) A bit more below... > bool mapping_inode_has_layout(struct vaddr_pin *vaddr_pin, struct page *page); > > /* Container for pinned pfns / pages */ > diff --git a/mm/gup.c b/mm/gup.c > index eeaa0ddd08a6..6d23f70d7847 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -2536,3 +2536,62 @@ int get_user_pages_fast(unsigned long start, int nr_pages, > return ret; > } > EXPORT_SYMBOL_GPL(get_user_pages_fast); > + > +/** > + * vaddr_pin_pages pin pages by virtual address and return the pages to the > + * user. > + * > + * @addr, start address What's with the commas? I thought kernel-doc wants colons, like this, right? @addr: start address > + * @nr_pages, number of pages to pin > + * @gup_flags, flags to use for the pin > + * @pages, array of pages returned > + * @vaddr_pin, initalized meta information this pin is to be associated > + * with. > + * > + * NOTE regarding vaddr_pin: > + * > + * Some callers can share pins via file descriptors to other processes. > + * Callers such as this should use the f_owner field of vaddr_pin to indicate > + * the file the fd points to. All other callers should use the mm this pin is > + * being made against. Usually "current->mm". > + * > + * Expects mmap_sem to be read locked. > + */ > +long vaddr_pin_pages(unsigned long addr, unsigned long nr_pages, > + unsigned int gup_flags, struct page **pages, > + struct vaddr_pin *vaddr_pin) > +{ > + long ret; > + > + gup_flags |= FOLL_LONGTERM; Is now the right time to introduce and use FOLL_PIN? If not, then I can always add it on top of this later, as part of gup-tracking patches. But you did point out that FOLL_LONGTERM is taking on additional meaning, and so maybe it's better to split that meaning up right from the start. > + > + if (!vaddr_pin || (!vaddr_pin->mm && !vaddr_pin->f_owner)) > + return -EINVAL; > + > + ret = __gup_longterm_locked(current, > + vaddr_pin->mm, > + addr, nr_pages, > + pages, NULL, gup_flags, > + vaddr_pin); > + return ret; > +} > +EXPORT_SYMBOL(vaddr_pin_pages); > + > +/** > + * vaddr_unpin_pages_dirty_lock - counterpart to vaddr_pin_pages > + * > + * @pages, array of pages returned > + * @nr_pages, number of pages in pages > + * @vaddr_pin, same information passed to vaddr_pin_pages > + * @make_dirty: whether to mark the pages dirty > + * > + * The semantics are similar to put_user_pages_dirty_lock but a vaddr_pin used > + * in vaddr_pin_pages should be passed back into this call for propper Typo: proper > + * tracking. > + */ > +void vaddr_unpin_pages_dirty_lock(struct page **pages, unsigned long nr_pages, > + struct vaddr_pin *vaddr_pin, bool make_dirty) > +{ > + __put_user_pages_dirty_lock(vaddr_pin, pages, nr_pages, make_dirty); > +} > +EXPORT_SYMBOL(vaddr_unpin_pages_dirty_lock); > OK, whew, I'm glad to see the updated _dirty_lock() API used here. :) thanks, -- John Hubbard NVIDIA
WARNING: multiple messages have this Message-ID (diff)
From: John Hubbard <jhubbard@nvidia.com> To: <ira.weiny@intel.com>, Andrew Morton <akpm@linux-foundation.org> Cc: Jason Gunthorpe <jgg@ziepe.ca>, Dan Williams <dan.j.williams@intel.com>, Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>, Theodore Ts'o <tytso@mit.edu>, Michal Hocko <mhocko@suse.com>, Dave Chinner <david@fromorbit.com>, <linux-xfs@vger.kernel.org>, <linux-rdma@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-fsdevel@vger.kernel.org>, <linux-nvdimm@lists.01.org>, <linux-ext4@vger.kernel.org>, <linux-mm@kvack.org> Subject: Re: [RFC PATCH v2 15/19] mm/gup: Introduce vaddr_pin_pages() Date: Fri, 9 Aug 2019 17:09:54 -0700 [thread overview] Message-ID: <6ed26a08-4371-9dc1-09eb-7b8a4689d93b@nvidia.com> (raw) Message-ID: <20190810000954.hJvr3Bs__BJLP-Vk17QjElHbIUP8W88ZHXDtXz3ghs4@z> (raw) In-Reply-To: <20190809225833.6657-16-ira.weiny@intel.com> On 8/9/19 3:58 PM, ira.weiny@intel.com wrote: > From: Ira Weiny <ira.weiny@intel.com> > > The addition of FOLL_LONGTERM has taken on additional meaning for CMA > pages. > > In addition subsystems such as RDMA require new information to be passed > to the GUP interface to track file owning information. As such a simple > FOLL_LONGTERM flag is no longer sufficient for these users to pin pages. > > Introduce a new GUP like call which takes the newly introduced vaddr_pin > information. Failure to pass the vaddr_pin object back to a vaddr_put* > call will result in a failure if pins were created on files during the > pin operation. > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > --- > Changes from list: > Change to vaddr_put_pages_dirty_lock > Change to vaddr_unpin_pages_dirty_lock > > include/linux/mm.h | 5 ++++ > mm/gup.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 64 insertions(+) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 657c947bda49..90c5802866df 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1603,6 +1603,11 @@ int account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc); > int __account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc, > struct task_struct *task, bool bypass_rlim); > > +long vaddr_pin_pages(unsigned long addr, unsigned long nr_pages, > + unsigned int gup_flags, struct page **pages, > + struct vaddr_pin *vaddr_pin); > +void vaddr_unpin_pages_dirty_lock(struct page **pages, unsigned long nr_pages, > + struct vaddr_pin *vaddr_pin, bool make_dirty); Hi Ira, OK, the API seems fine to me, anyway. :) A bit more below... > bool mapping_inode_has_layout(struct vaddr_pin *vaddr_pin, struct page *page); > > /* Container for pinned pfns / pages */ > diff --git a/mm/gup.c b/mm/gup.c > index eeaa0ddd08a6..6d23f70d7847 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -2536,3 +2536,62 @@ int get_user_pages_fast(unsigned long start, int nr_pages, > return ret; > } > EXPORT_SYMBOL_GPL(get_user_pages_fast); > + > +/** > + * vaddr_pin_pages pin pages by virtual address and return the pages to the > + * user. > + * > + * @addr, start address What's with the commas? I thought kernel-doc wants colons, like this, right? @addr: start address > + * @nr_pages, number of pages to pin > + * @gup_flags, flags to use for the pin > + * @pages, array of pages returned > + * @vaddr_pin, initalized meta information this pin is to be associated > + * with. > + * > + * NOTE regarding vaddr_pin: > + * > + * Some callers can share pins via file descriptors to other processes. > + * Callers such as this should use the f_owner field of vaddr_pin to indicate > + * the file the fd points to. All other callers should use the mm this pin is > + * being made against. Usually "current->mm". > + * > + * Expects mmap_sem to be read locked. > + */ > +long vaddr_pin_pages(unsigned long addr, unsigned long nr_pages, > + unsigned int gup_flags, struct page **pages, > + struct vaddr_pin *vaddr_pin) > +{ > + long ret; > + > + gup_flags |= FOLL_LONGTERM; Is now the right time to introduce and use FOLL_PIN? If not, then I can always add it on top of this later, as part of gup-tracking patches. But you did point out that FOLL_LONGTERM is taking on additional meaning, and so maybe it's better to split that meaning up right from the start. > + > + if (!vaddr_pin || (!vaddr_pin->mm && !vaddr_pin->f_owner)) > + return -EINVAL; > + > + ret = __gup_longterm_locked(current, > + vaddr_pin->mm, > + addr, nr_pages, > + pages, NULL, gup_flags, > + vaddr_pin); > + return ret; > +} > +EXPORT_SYMBOL(vaddr_pin_pages); > + > +/** > + * vaddr_unpin_pages_dirty_lock - counterpart to vaddr_pin_pages > + * > + * @pages, array of pages returned > + * @nr_pages, number of pages in pages > + * @vaddr_pin, same information passed to vaddr_pin_pages > + * @make_dirty: whether to mark the pages dirty > + * > + * The semantics are similar to put_user_pages_dirty_lock but a vaddr_pin used > + * in vaddr_pin_pages should be passed back into this call for propper Typo: proper > + * tracking. > + */ > +void vaddr_unpin_pages_dirty_lock(struct page **pages, unsigned long nr_pages, > + struct vaddr_pin *vaddr_pin, bool make_dirty) > +{ > + __put_user_pages_dirty_lock(vaddr_pin, pages, nr_pages, make_dirty); > +} > +EXPORT_SYMBOL(vaddr_unpin_pages_dirty_lock); > OK, whew, I'm glad to see the updated _dirty_lock() API used here. :) thanks, -- John Hubbard NVIDIA
next prev parent reply other threads:[~2019-08-10 0:09 UTC|newest] Thread overview: 118+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-08-09 22:58 [RFC PATCH v2 00/19] RDMA/FS DAX truncate proposal V1,000,002 ;-) ira.weiny 2019-08-09 22:58 ` [RFC PATCH v2 01/19] fs/locks: Export F_LAYOUT lease to user space ira.weiny 2019-08-09 23:52 ` Dave Chinner 2019-08-12 17:36 ` Ira Weiny 2019-08-14 8:05 ` Dave Chinner 2019-08-14 11:21 ` Jeff Layton 2019-08-14 11:38 ` Dave Chinner 2019-08-09 22:58 ` [RFC PATCH v2 02/19] fs/locks: Add Exclusive flag to user Layout lease ira.weiny 2019-08-14 14:15 ` Jeff Layton 2019-08-14 21:56 ` Dave Chinner 2019-08-26 10:41 ` Jeff Layton 2019-08-29 23:34 ` Ira Weiny 2019-09-04 12:52 ` Jeff Layton 2019-09-04 23:12 ` John Hubbard 2019-08-09 22:58 ` [RFC PATCH v2 03/19] mm/gup: Pass flags down to __gup_device_huge* calls ira.weiny 2019-08-09 22:58 ` [RFC PATCH v2 04/19] mm/gup: Ensure F_LAYOUT lease is held prior to GUP'ing pages ira.weiny 2019-08-09 22:58 ` [RFC PATCH v2 05/19] fs/ext4: Teach ext4 to break layout leases ira.weiny 2019-08-09 22:58 ` [RFC PATCH v2 06/19] fs/ext4: Teach dax_layout_busy_page() to operate on a sub-range ira.weiny 2019-08-23 15:18 ` Vivek Goyal 2019-08-29 18:52 ` Ira Weiny 2019-08-09 22:58 ` [RFC PATCH v2 07/19] fs/xfs: Teach xfs to use new dax_layout_busy_page() ira.weiny 2019-08-09 23:30 ` Dave Chinner 2019-08-12 18:05 ` Ira Weiny 2019-08-14 8:04 ` Dave Chinner 2019-08-09 22:58 ` [RFC PATCH v2 08/19] fs/xfs: Fail truncate if page lease can't be broken ira.weiny 2019-08-09 23:22 ` Dave Chinner 2019-08-12 18:08 ` Ira Weiny 2019-08-09 22:58 ` [RFC PATCH v2 09/19] mm/gup: Introduce vaddr_pin structure ira.weiny 2019-08-10 0:06 ` John Hubbard 2019-08-10 0:06 ` John Hubbard 2019-08-09 22:58 ` [RFC PATCH v2 10/19] mm/gup: Pass a NULL vaddr_pin through GUP fast ira.weiny 2019-08-10 0:06 ` John Hubbard 2019-08-10 0:06 ` John Hubbard 2019-08-09 22:58 ` [RFC PATCH v2 11/19] mm/gup: Pass follow_page_context further down the call stack ira.weiny 2019-08-10 0:18 ` John Hubbard 2019-08-10 0:18 ` John Hubbard 2019-08-12 19:01 ` Ira Weiny 2019-08-09 22:58 ` [RFC PATCH v2 12/19] mm/gup: Prep put_user_pages() to take an vaddr_pin struct ira.weiny 2019-08-10 0:30 ` John Hubbard 2019-08-10 0:30 ` John Hubbard 2019-08-12 20:46 ` Ira Weiny 2019-08-09 22:58 ` [RFC PATCH v2 13/19] {mm,file}: Add file_pins objects ira.weiny 2019-08-09 22:58 ` [RFC PATCH v2 14/19] fs/locks: Associate file pins while performing GUP ira.weiny 2019-08-09 22:58 ` [RFC PATCH v2 15/19] mm/gup: Introduce vaddr_pin_pages() ira.weiny 2019-08-10 0:09 ` John Hubbard [this message] 2019-08-10 0:09 ` John Hubbard 2019-08-12 21:00 ` Ira Weiny 2019-08-12 21:20 ` John Hubbard 2019-08-12 21:20 ` John Hubbard 2019-08-11 23:07 ` John Hubbard 2019-08-11 23:07 ` John Hubbard 2019-08-12 21:01 ` Ira Weiny 2019-08-12 12:28 ` Jason Gunthorpe 2019-08-12 21:48 ` Ira Weiny 2019-08-13 11:47 ` Jason Gunthorpe 2019-08-13 17:46 ` Ira Weiny 2019-08-13 17:56 ` John Hubbard 2019-08-13 17:56 ` John Hubbard 2019-08-09 22:58 ` [RFC PATCH v2 16/19] RDMA/uverbs: Add back pointer to system file object ira.weiny 2019-08-12 13:00 ` Jason Gunthorpe 2019-08-12 17:28 ` Ira Weiny 2019-08-12 17:56 ` Jason Gunthorpe 2019-08-12 21:15 ` Ira Weiny 2019-08-13 11:48 ` Jason Gunthorpe 2019-08-13 17:41 ` Ira Weiny 2019-08-13 18:00 ` Jason Gunthorpe 2019-08-13 20:38 ` Ira Weiny 2019-08-14 12:23 ` Jason Gunthorpe 2019-08-14 17:50 ` Ira Weiny 2019-08-14 18:15 ` Jason Gunthorpe 2019-09-04 22:25 ` Ira Weiny 2019-09-11 8:19 ` Jason Gunthorpe 2019-08-09 22:58 ` [RFC PATCH v2 17/19] RDMA/umem: Convert to vaddr_[pin|unpin]* operations ira.weiny 2019-08-09 22:58 ` [RFC PATCH v2 18/19] {mm,procfs}: Add display file_pins proc ira.weiny 2019-08-09 22:58 ` [RFC PATCH v2 19/19] mm/gup: Remove FOLL_LONGTERM DAX exclusion ira.weiny 2019-08-14 10:17 ` [RFC PATCH v2 00/19] RDMA/FS DAX truncate proposal V1,000,002 ;-) Jan Kara 2019-08-14 18:08 ` Ira Weiny 2019-08-15 13:05 ` Jan Kara 2019-08-16 19:05 ` Ira Weiny 2019-08-16 23:20 ` [RFC PATCH v2 00/19] RDMA/FS DAX truncate proposal V1,000,002 ; -) Ira Weiny 2019-08-19 6:36 ` Jan Kara 2019-08-17 2:26 ` [RFC PATCH v2 00/19] RDMA/FS DAX truncate proposal V1,000,002 ;-) Dave Chinner 2019-08-19 6:34 ` Jan Kara 2019-08-19 9:24 ` Dave Chinner 2019-08-19 12:38 ` Jason Gunthorpe 2019-08-19 21:53 ` Ira Weiny 2019-08-20 1:12 ` Dave Chinner 2019-08-20 11:55 ` Jason Gunthorpe 2019-08-21 18:02 ` Ira Weiny 2019-08-21 18:13 ` Jason Gunthorpe 2019-08-21 18:22 ` John Hubbard 2019-08-21 18:57 ` Ira Weiny 2019-08-21 19:06 ` Ira Weiny 2019-08-21 19:48 ` Jason Gunthorpe 2019-08-21 20:44 ` Ira Weiny 2019-08-21 23:49 ` Jason Gunthorpe 2019-08-23 3:23 ` Dave Chinner 2019-08-23 12:04 ` Jason Gunthorpe 2019-08-24 0:11 ` Dave Chinner 2019-08-24 5:08 ` Ira Weiny 2019-08-26 5:55 ` Dave Chinner 2019-08-29 2:02 ` Ira Weiny 2019-08-29 3:27 ` John Hubbard 2019-08-29 16:16 ` Ira Weiny 2019-09-02 22:26 ` Dave Chinner 2019-09-04 16:54 ` Ira Weiny 2019-08-25 19:39 ` Jason Gunthorpe 2019-08-24 4:49 ` Ira Weiny 2019-08-25 19:40 ` Jason Gunthorpe 2019-08-23 0:59 ` Dave Chinner 2019-08-23 17:15 ` Ira Weiny 2019-08-24 0:18 ` Dave Chinner 2019-08-20 0:05 ` John Hubbard 2019-08-20 1:20 ` Dave Chinner 2019-08-20 3:09 ` John Hubbard 2019-08-20 3:36 ` Dave Chinner 2019-08-21 18:43 ` John Hubbard 2019-08-21 19:09 ` Ira Weiny
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