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  1. 04 5月, 2017 13 次提交
  3. 01 5月, 2017 2 次提交
    • H
      mm: remove AVR32 arch special handling in mm/Kconfig · 01e7bc24
      由 Hans-Christian Noren Egtvedt 提交于 
      AVR32 architecture has been removed from the Linux kernel sources, hence
clean up the special handling setting two quicklists by default in
mm/Kconfig.
Signed-off-by: NHans-Christian Noren Egtvedt <egtvedt@samfundet.no>
      01e7bc24
    • D
      mm, zone_device: Replace {get, put}_zone_device_page() with a single reference to fix pmem crash · 71389703
      由 Dan Williams 提交于 
      The x86 conversion to the generic GUP code included a small change which causes
crashes and data corruption in the pmem code - not good.

The root cause is that the /dev/pmem driver code implicitly relies on the x86
get_user_pages() implementation doing a get_page() on the page refcount, because
get_page() does a get_zone_device_page() which properly refcounts pmem's separate
page struct arrays that are not present in the regular page struct structures.
(The pmem driver does this because it can cover huge memory areas.)

But the x86 conversion to the generic GUP code changed the get_page() to
page_cache_get_speculative() which is faster but doesn't do the
get_zone_device_page() call the pmem code relies on.

One way to solve the regression would be to change the generic GUP code to use
get_page(), but that would slow things down a bit and punish other generic-GUP
using architectures for an x86-ism they did not care about. (Arguably the pmem
driver was probably not working reliably for them: but nvdimm is an Intel
feature, so non-x86 exposure is probably still limited.)

So restructure the pmem code's interface with the MM instead: get rid of the
get/put_zone_device_page() distinction, integrate put_zone_device_page() into
__put_page() and and restructure the pmem completion-wait and teardown machinery:

Kirill points out that the calls to {get,put}_dev_pagemap() can be
removed from the mm fast path if we take a single get_dev_pagemap()
reference to signify that the page is alive and use the final put of the
page to drop that reference.

This does require some care to make sure that any waits for the
percpu_ref to drop to zero occur *after* devm_memremap_page_release(),
since it now maintains its own elevated reference.

This speeds up things while also making the pmem refcounting more robust going
forward.
Suggested-by: NKirill Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: NKirill Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Reviewed-by: NLogan Gunthorpe <logang@deltatee.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/149339998297.24933.1129582806028305912.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      71389703
  5. 23 4月, 2017 1 次提交
    • I
      Revert "x86/mm/gup: Switch GUP to the generic get_user_page_fast() implementation" · 6dd29b3d
      由 Ingo Molnar 提交于 
      This reverts commit 2947ba05.

Dan Williams reported dax-pmem kernel warnings with the following signature:

   WARNING: CPU: 8 PID: 245 at lib/percpu-refcount.c:155 percpu_ref_switch_to_atomic_rcu+0x1f5/0x200
   percpu ref (dax_pmem_percpu_release [dax_pmem]) <= 0 (0) after switching to atomic

... and bisected it to this commit, which suggests possible memory corruption
caused by the x86 fast-GUP conversion.

He also pointed out:

 "
  This is similar to the backtrace when we were not properly handling
  pud faults and was fixed with this commit: 220ced16 "mm: fix
  get_user_pages() vs device-dax pud mappings"

  I've found some missing _devmap checks in the generic
  get_user_pages_fast() path, but this does not fix the regression
  [...]
 "

So given that there are known bugs, and a pretty robust looking bisection
points to this commit suggesting that are unknown bugs in the conversion
as well, revert it for the time being - we'll re-try in v4.13.
Reported-by: NDan Williams <dan.j.williams@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: aneesh.kumar@linux.vnet.ibm.com
Cc: dann.frazier@canonical.com
Cc: dave.hansen@intel.com
Cc: steve.capper@linaro.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      6dd29b3d
  7. 22 4月, 2017 2 次提交
  9. 21 4月, 2017 7 次提交
  11. 20 4月, 2017 1 次提交
    • M
      mm: make mm_percpu_wq non freezable · 80d136e1
      由 Michal Hocko 提交于 
      Geert has reported a freeze during PM resume and some additional
debugging has shown that the device_resume worker cannot make a forward
progress because it waits for an event which is stuck waiting in
drain_all_pages:

  INFO: task kworker/u4:0:5 blocked for more than 120 seconds.
        Not tainted 4.11.0-rc7-koelsch-00029-g005882e5-dirty #3476
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  kworker/u4:0    D    0     5      2 0x00000000
  Workqueue: events_unbound async_run_entry_fn
    __schedule
    schedule
    schedule_timeout
    wait_for_common
    dpm_wait_for_superior
    device_resume
    async_resume
    async_run_entry_fn
    process_one_work
    worker_thread
    kthread
  [...]
  bash            D    0  1703   1694 0x00000000
    __schedule
    schedule
    schedule_timeout
    wait_for_common
    flush_work
    drain_all_pages
    start_isolate_page_range
    alloc_contig_range
    cma_alloc
    __alloc_from_contiguous
    cma_allocator_alloc
    __dma_alloc
    arm_dma_alloc
    sh_eth_ring_init
    sh_eth_open
    sh_eth_resume
    dpm_run_callback
    device_resume
    dpm_resume
    dpm_resume_end
    suspend_devices_and_enter
    pm_suspend
    state_store
    kernfs_fop_write
    __vfs_write
    vfs_write
    SyS_write
  [...]
  Showing busy workqueues and worker pools:
  [...]
  workqueue mm_percpu_wq: flags=0xc
    pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=0/0
      delayed: drain_local_pages_wq, vmstat_update
    pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=0/0
      delayed: drain_local_pages_wq BAR(1703), vmstat_update

Tetsuo has properly noted that mm_percpu_wq is created as WQ_FREEZABLE
so it is frozen this early during resume so we are effectively
deadlocked.  Fix this by dropping WQ_FREEZABLE when creating
mm_percpu_wq.  We really want to have it operational all the time.

Fixes: ce612879 ("mm: move pcp and lru-pcp draining into single wq")
Reported-and-tested-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Debugged-by: NTetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      80d136e1
  13. 14 4月, 2017 5 次提交
  15. 09 4月, 2017 1 次提交
  17. 08 4月, 2017 5 次提交
  19. 06 4月, 2017 1 次提交
  21. 05 4月, 2017 1 次提交
  23. 03 4月, 2017 1 次提交
    • M
      kernel-api.rst: fix a series of errors when parsing C files · 0e056eb5
      由 mchehab@s-opensource.com 提交于 
      ./lib/string.c:134: WARNING: Inline emphasis start-string without end-string.
./mm/filemap.c:522: WARNING: Inline interpreted text or phrase reference start-string without end-string.
./mm/filemap.c:1283: ERROR: Unexpected indentation.
./mm/filemap.c:3003: WARNING: Inline interpreted text or phrase reference start-string without end-string.
./mm/vmalloc.c:1544: WARNING: Inline emphasis start-string without end-string.
./mm/page_alloc.c:4245: ERROR: Unexpected indentation.
./ipc/util.c:676: ERROR: Unexpected indentation.
./drivers/pci/irq.c:35: WARNING: Block quote ends without a blank line; unexpected unindent.
./security/security.c:109: ERROR: Unexpected indentation.
./security/security.c:110: WARNING: Definition list ends without a blank line; unexpected unindent.
./block/genhd.c:275: WARNING: Inline strong start-string without end-string.
./block/genhd.c:283: WARNING: Inline strong start-string without end-string.
./include/linux/clk.h:134: WARNING: Inline emphasis start-string without end-string.
./include/linux/clk.h:134: WARNING: Inline emphasis start-string without end-string.
./ipc/util.c:477: ERROR: Unknown target name: "s".
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>
      0e056eb5