Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 21 12月, 2012 3 次提交
    • D
      CacheFiles: Fix the marking of cached pages · c4d6d8db
      由 David Howells 提交于 
      Under some circumstances CacheFiles defers the marking of pages with PG_fscache
so that it can take advantage of pagevecs to reduce the number of calls to
fscache_mark_pages_cached() and the netfs's hook to keep track of this.

There are, however, two problems with this:

 (1) It can lead to the PG_fscache mark being applied _after_ the page is set
     PG_uptodate and unlocked (by the call to fscache_end_io()).

 (2) CacheFiles's ref on the page is dropped immediately following
     fscache_end_io() - and so may not still be held when the mark is applied.
     This can lead to the page being passed back to the allocator before the
     mark is applied.

Fix this by, where appropriate, marking the page before calling
fscache_end_io() and releasing the page.  This means that we can't take
advantage of pagevecs and have to make a separate call for each page to the
marking routines.

The symptoms of this are Bad Page state errors cropping up under memory
pressure, for example:

BUG: Bad page state in process tar  pfn:002da
page:ffffea0000009fb0 count:0 mapcount:0 mapping:          (null) index:0x1447
page flags: 0x1000(private_2)
Pid: 4574, comm: tar Tainted: G        W   3.1.0-rc4-fsdevel+ #1064
Call Trace:
 [<ffffffff8109583c>] ? dump_page+0xb9/0xbe
 [<ffffffff81095916>] bad_page+0xd5/0xea
 [<ffffffff81095d82>] get_page_from_freelist+0x35b/0x46a
 [<ffffffff810961f3>] __alloc_pages_nodemask+0x362/0x662
 [<ffffffff810989da>] __do_page_cache_readahead+0x13a/0x267
 [<ffffffff81098942>] ? __do_page_cache_readahead+0xa2/0x267
 [<ffffffff81098d7b>] ra_submit+0x1c/0x20
 [<ffffffff8109900a>] ondemand_readahead+0x28b/0x29a
 [<ffffffff81098ee2>] ? ondemand_readahead+0x163/0x29a
 [<ffffffff810990ce>] page_cache_sync_readahead+0x38/0x3a
 [<ffffffff81091d8a>] generic_file_aio_read+0x2ab/0x67e
 [<ffffffffa008cfbe>] nfs_file_read+0xa4/0xc9 [nfs]
 [<ffffffff810c22c4>] do_sync_read+0xba/0xfa
 [<ffffffff81177a47>] ? security_file_permission+0x7b/0x84
 [<ffffffff810c25dd>] ? rw_verify_area+0xab/0xc8
 [<ffffffff810c29a4>] vfs_read+0xaa/0x13a
 [<ffffffff810c2a79>] sys_read+0x45/0x6c
 [<ffffffff813ac37b>] system_call_fastpath+0x16/0x1b

As can be seen, PG_private_2 (== PG_fscache) is set in the page flags.

Instrumenting fscache_mark_pages_cached() to verify whether page->mapping was
set appropriately showed that sometimes it wasn't.  This led to the discovery
that sometimes the page has apparently been reclaimed by the time the marker
got to see it.
Reported-by: NM. Stevens <m@tippett.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
      c4d6d8db
    • V
      ARM: OMAP: Fix build breakage due to missing include in i2c.c · 18000985
      由 Vaibhav Bedia 提交于 
      Merge commit 752451f0 ("Merge branch 'i2c-embedded/for-next' of
git://git.pengutronix.de/git/wsa/linux") resulted in a build breakage
for OMAP

  arch/arm/mach-omap2/i2c.c: In function 'omap_pm_set_max_mpu_wakeup_lat_compat':
  arch/arm/mach-omap2/i2c.c:130:2: error: implicit declaration of function 'omap_pm_set_max_mpu_wakeup_lat'
  make[1]: *** [arch/arm/mach-omap2/i2c.o] Error 1

Fix this by including the appropriate header file with the function
prototype.
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NVaibhav Bedia <vaibhav.bedia@ti.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      18000985
    • L
      Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux · b7dfde95
      由 Linus Torvalds 提交于 
      Pull virtio update from Rusty Russell:
 "Some nice cleanups, and even a patch my wife did as a "live" demo for
  Latinoware 2012.

  There's a slightly non-trivial merge in virtio-net, as we cleaned up
  the virtio add_buf interface while DaveM accepted the mq virtio-net
  patches."

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (27 commits)
  virtio_console: Add support for remoteproc serial
  virtio_console: Merge struct buffer_token into struct port_buffer
  virtio: add drv_to_virtio to make code clearly
  virtio: use dev_to_virtio wrapper in virtio
  virtio-mmio: Fix irq parsing in command line parameter
  virtio_console: Free buffers from out-queue upon close
  virtio: Convert dev_printk(KERN_<LEVEL> to dev_<level>(
  virtio_console: Use kmalloc instead of kzalloc
  virtio_console: Free buffer if splice fails
  virtio: tools: make it clear that virtqueue_add_buf() no longer returns > 0
  virtio: scsi: make it clear that virtqueue_add_buf() no longer returns > 0
  virtio: rpmsg: make it clear that virtqueue_add_buf() no longer returns > 0
  virtio: net: make it clear that virtqueue_add_buf() no longer returns > 0
  virtio: console: make it clear that virtqueue_add_buf() no longer returns > 0
  virtio: make virtqueue_add_buf() returning 0 on success, not capacity.
  virtio: console: don't rely on virtqueue_add_buf() returning capacity.
  virtio_net: don't rely on virtqueue_add_buf() returning capacity.
  virtio-net: remove unused skb_vnet_hdr->num_sg field
  virtio-net: correct capacity math on ring full
  virtio: move queue_index and num_free fields into core struct virtqueue.
  ...
      b7dfde95
  3. 20 12月, 2012 37 次提交