forked from Minki/linux
eaf4d22a9e
Patch series "vhost, docs: convert to pin_user_pages(), new "case 5"" It recently became clear to me that there are some get_user_pages*() callers that don't fit neatly into any of the four cases that are so far listed in pin_user_pages.rst. vhost.c is one of those. Add a Case 5 to the documentation, and refer to that when converting vhost.c. Thanks to Jan Kara for helping me (again) in understanding the interaction between get_user_pages() and page writeback [1]. This is based on today's mmotm, which has a nearby patch to pin_user_pages.rst that rewords cases 3 and 4. Note that I have only compile-tested the vhost.c patch, although that does also include cross-compiling for a few other arches. Any run-time testing would be greatly appreciated. [1] https://lore.kernel.org/r/20200529070343.GL14550@quack2.suse.cz This patch (of 2): There are four cases listed in pin_user_pages.rst. These are intended to help developers figure out whether to use get_user_pages*(), or pin_user_pages*(). However, the four cases do not cover all the situations. For example, drivers/vhost/vhost.c has a "pin, write to page, set page dirty, unpin" case. Add a fifth case, to help explain that there is a general pattern that requires pin_user_pages*() API calls. [jhubbard@nvidia.com: v2] Link: http://lkml.kernel.org/r/20200601052633.853874-2-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: "Michael S . Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Link: http://lkml.kernel.org/r/20200529234309.484480-1-jhubbard@nvidia.com Link: http://lkml.kernel.org/r/20200529234309.484480-2-jhubbard@nvidia.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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| .. | ||
| irq | ||
| assoc_array.rst | ||
| atomic_ops.rst | ||
| boot-time-mm.rst | ||
| cachetlb.rst | ||
| circular-buffers.rst | ||
| cpu_hotplug.rst | ||
| debug-objects.rst | ||
| debugging-via-ohci1394.rst | ||
| dma-api-howto.rst | ||
| dma-api.rst | ||
| dma-attributes.rst | ||
| dma-isa-lpc.rst | ||
| errseq.rst | ||
| genalloc.rst | ||
| generic-radix-tree.rst | ||
| genericirq.rst | ||
| gfp_mask-from-fs-io.rst | ||
| idr.rst | ||
| index.rst | ||
| kernel-api.rst | ||
| kobject.rst | ||
| kref.rst | ||
| librs.rst | ||
| local_ops.rst | ||
| memory-allocation.rst | ||
| memory-hotplug.rst | ||
| mm-api.rst | ||
| packing.rst | ||
| padata.rst | ||
| pin_user_pages.rst | ||
| printk-basics.rst | ||
| printk-formats.rst | ||
| protection-keys.rst | ||
| rbtree.rst | ||
| refcount-vs-atomic.rst | ||
| symbol-namespaces.rst | ||
| timekeeping.rst | ||
| tracepoint.rst | ||
| workqueue.rst | ||
| xarray.rst | ||