From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, corbet@lwn.net, david@fromorbit.com,
jack@suse.cz, jasowang@redhat.com, jglisse@redhat.com,
jhubbard@nvidia.com, jrdr.linux@gmail.com, linux-mm@kvack.org,
mm-commits@vger.kernel.org, mst@redhat.com,
pankaj.gupta.linux@gmail.com, torvalds@linux-foundation.org,
vbabka@suse.cz
Subject: [patch 22/54] vhost: convert get_user_pages() --> pin_user_pages()
Date: Sun, 07 Jun 2020 21:41:15 -0700 [thread overview]
Message-ID: <20200608044115.tMvGFNio5%akpm@linux-foundation.org> (raw)
In-Reply-To: <20200607212615.b050e41fac139a1e16fe00bd@linux-foundation.org>
From: John Hubbard <jhubbard@nvidia.com>
Subject: vhost: convert get_user_pages() --> pin_user_pages()
This code was using get_user_pages*(), in approximately a "Case 5"
scenario (accessing the data within a page), using the categorization from
[1]. That means that it's time to convert the get_user_pages*() +
put_page() calls to pin_user_pages*() + unpin_user_pages() calls.
There is some helpful background in [2]: basically, this is a small part
of fixing a long-standing disconnect between pinning pages, and file
systems' use of those pages.
[1] Documentation/core-api/pin_user_pages.rst
[2] "Explicit pinning of user-space pages":
https://lwn.net/Articles/807108/
Link: http://lkml.kernel.org/r/20200529234309.484480-3-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
drivers/vhost/vhost.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
--- a/drivers/vhost/vhost.c~vhost-convert-get_user_pages-pin_user_pages
+++ a/drivers/vhost/vhost.c
@@ -1762,15 +1762,14 @@ static int set_bit_to_user(int nr, void
int bit = nr + (log % PAGE_SIZE) * 8;
int r;
- r = get_user_pages_fast(log, 1, FOLL_WRITE, &page);
+ r = pin_user_pages_fast(log, 1, FOLL_WRITE, &page);
if (r < 0)
return r;
BUG_ON(r != 1);
base = kmap_atomic(page);
set_bit(bit, base);
kunmap_atomic(base);
- set_page_dirty_lock(page);
- put_page(page);
+ unpin_user_pages_dirty_lock(&page, 1, true);
return 0;
}
_
next prev parent reply other threads:[~2020-06-08 4:41 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200607212615.b050e41fac139a1e16fe00bd@linux-foundation.org>
2020-06-08 4:40 ` [patch 01/54] mm/page_idle.c: skip offline pages Andrew Morton
2020-06-08 4:40 ` [patch 02/54] ipc/msg: add missing annotation for freeque() Andrew Morton
2020-06-08 4:40 ` [patch 03/54] ipc/namespace.c: use a work queue to free_ipc Andrew Morton
2020-06-08 4:40 ` [patch 04/54] dynamic_debug: add an option to enable dynamic debug for modules only Andrew Morton
2020-06-08 4:58 ` 答复: " 翟京 (Orson Zhai)
2020-06-08 4:40 ` [patch 05/54] kernel: add panic_on_taint Andrew Morton
2020-06-08 4:40 ` [patch 06/54] xarray.h: correct return code documentation for xa_store_{bh,irq}() Andrew Morton
2020-06-08 4:40 ` [patch 07/54] kernel/sysctl: support setting sysctl parameters from kernel command line Andrew Morton
2020-06-08 4:40 ` [patch 08/54] kernel/sysctl: support handling command line aliases Andrew Morton
2020-06-08 4:40 ` [patch 09/54] kernel/hung_task convert hung_task_panic boot parameter to sysctl Andrew Morton
2020-06-08 4:40 ` [patch 10/54] tools/testing/selftests/sysctl/sysctl.sh: support CONFIG_TEST_SYSCTL=y Andrew Morton
2020-06-08 4:40 ` [patch 11/54] lib/test_sysctl: support testing of sysctl. boot parameter Andrew Morton
2020-06-08 4:40 ` [patch 12/54] kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases Andrew Morton
2020-06-08 4:40 ` [patch 13/54] kernel/hung_task.c: introduce sysctl to print all traces when a hung task is detected Andrew Morton
2020-06-08 4:40 ` [patch 14/54] panic: add sysctl to dump all CPUs backtraces on oops event Andrew Morton
2020-06-08 4:40 ` [patch 15/54] kernel/sysctl.c: ignore out-of-range taint bits introduced via kernel.tainted Andrew Morton
2020-06-08 4:40 ` [patch 16/54] mm/gup.c: convert to use get_user_{page|pages}_fast_only() Andrew Morton
2020-06-08 4:40 ` [patch 17/54] mm/gup: update pin_user_pages.rst for "case 3" (mmu notifiers) Andrew Morton
2020-06-08 4:41 ` [patch 18/54] mm/gup: introduce pin_user_pages_locked() Andrew Morton
2020-06-08 4:41 ` [patch 19/54] mm/gup: frame_vector: convert get_user_pages() --> pin_user_pages() Andrew Morton
2020-06-08 4:41 ` [patch 20/54] mm/gup: documentation fix for pin_user_pages*() APIs Andrew Morton
2020-06-08 4:41 ` [patch 21/54] docs: mm/gup: pin_user_pages.rst: add a "case 5" Andrew Morton
2020-06-08 4:41 ` Andrew Morton [this message]
2020-06-08 4:41 ` [patch 23/54] mm/mmap.c: add more sanity checks to get_unmapped_area() Andrew Morton
2020-06-08 4:41 ` [patch 24/54] mm/mmap.c: do not allow mappings outside of allowed limits Andrew Morton
2020-06-08 17:50 ` Linus Torvalds
2020-06-08 17:55 ` Linus Torvalds
2020-06-08 4:41 ` [patch 25/54] arm: fix the flush_icache_range arguments in set_fiq_handler Andrew Morton
2020-06-08 4:41 ` [patch 26/54] nds32: unexport flush_icache_page Andrew Morton
2020-06-08 4:41 ` [patch 27/54] powerpc: unexport flush_icache_user_range Andrew Morton
2020-06-08 4:41 ` [patch 28/54] unicore32: remove flush_cache_user_range Andrew Morton
2020-06-08 4:41 ` [patch 29/54] asm-generic: fix the inclusion guards for cacheflush.h Andrew Morton
2020-06-08 4:41 ` [patch 30/54] asm-generic: don't include <linux/mm.h> in cacheflush.h Andrew Morton
2020-06-08 4:41 ` [patch 31/54] asm-generic: improve the flush_dcache_page stub Andrew Morton
2020-06-08 4:41 ` [patch 32/54] alpha: use asm-generic/cacheflush.h Andrew Morton
2020-06-08 4:41 ` [patch 33/54] arm64: " Andrew Morton
2020-06-08 4:41 ` [patch 34/54] c6x: " Andrew Morton
2020-06-08 4:41 ` [patch 35/54] hexagon: " Andrew Morton
2020-06-08 4:42 ` [patch 36/54] ia64: " Andrew Morton
2020-06-08 4:42 ` [patch 37/54] microblaze: " Andrew Morton
2020-06-08 4:42 ` [patch 38/54] m68knommu: " Andrew Morton
2020-06-08 4:42 ` [patch 39/54] openrisc: " Andrew Morton
2020-06-08 4:42 ` [patch 40/54] powerpc: " Andrew Morton
2020-06-08 4:42 ` [patch 41/54] riscv: " Andrew Morton
2020-06-08 4:42 ` [patch 42/54] arm,sparc,unicore32: remove flush_icache_user_range Andrew Morton
2020-06-08 4:42 ` [patch 43/54] mm: rename flush_icache_user_range to flush_icache_user_page Andrew Morton
2020-06-08 4:42 ` [patch 44/54] asm-generic: add a flush_icache_user_range stub Andrew Morton
2020-06-08 4:42 ` [patch 45/54] sh: implement flush_icache_user_range Andrew Morton
2020-06-08 4:42 ` [patch 46/54] xtensa: " Andrew Morton
2020-06-08 4:42 ` [patch 47/54] arm: rename flush_cache_user_range to flush_icache_user_range Andrew Morton
2020-06-08 4:42 ` [patch 48/54] m68k: implement flush_icache_user_range Andrew Morton
2020-06-08 4:42 ` [patch 49/54] exec: only build read_code when needed Andrew Morton
2020-06-08 4:42 ` [patch 50/54] exec: use flush_icache_user_range in read_code Andrew Morton
2020-06-08 4:42 ` [patch 51/54] binfmt_flat: use flush_icache_user_range Andrew Morton
2020-06-08 4:42 ` [patch 52/54] nommu: use flush_icache_user_range in brk and mmap Andrew Morton
2020-06-08 4:42 ` [patch 53/54] module: move the set_fs hack for flush_icache_range to m68k Andrew Morton
2020-06-08 4:42 ` [patch 54/54] doc: cgroup: update note about conditions when oom killer is invoked Andrew Morton
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