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  1. 25 Jun, 2009 2 commits
  3. 24 Jun, 2009 1 commit
    • Cliff Wickman's avatar
      x86: Fix uv bau sending buffer initialization · 9c26f52b
      Cliff Wickman authored 
      The initialization of the UV Broadcast Assist Unit's sending
buffers was making an invalid assumption about the
initialization of an MMR that defines its address.

The BIOS will not be providing that MMR.  So
uv_activation_descriptor_init() should unconditionally set it.

Tested on UV simulator.
Signed-off-by: default avatarCliff Wickman <cpw@sgi.com>
Cc: <stable@kernel.org> # for v2.6.30.x
LKML-Reference: <E1MJTfj-0005i1-W8@eag09.americas.sgi.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      9c26f52b
  5. 23 Jun, 2009 2 commits
  7. 22 Jun, 2009 9 commits
    • Ingo Molnar's avatar
      Merge branch 'for-tip' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu into x86/urgent · b7f797cb
      Ingo Molnar authored
      b7f797cb
    • Tejun Heo's avatar
      x86: ensure percpu lpage doesn't consume too much vmalloc space · 0017c869
      Tejun Heo authored 
      On extreme configuration (e.g. 32bit 32-way NUMA machine), lpage
percpu first chunk allocator can consume too much of vmalloc space.
Make it fall back to 4k allocator if the consumption goes over 20%.

[ Impact: add sanity check for lpage percpu first chunk allocator ]
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reported-by: default avatarJan Beulich <JBeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
      0017c869
    • Tejun Heo's avatar
      x86: implement percpu_alloc kernel parameter · fa8a7094
      Tejun Heo authored 
      According to Andi, it isn't clear whether lpage allocator is worth the
trouble as there are many processors where PMD TLB is far scarcer than
PTE TLB.  The advantage or disadvantage probably depends on the actual
size of percpu area and specific processor.  As performance
degradation due to TLB pressure tends to be highly workload specific
and subtle, it is difficult to decide which way to go without more
data.

This patch implements percpu_alloc kernel parameter to allow selecting
which first chunk allocator to use to ease debugging and testing.

While at it, make sure all the failure paths report why something
failed to help determining why certain allocator isn't working.  Also,
kill the "Great future plan" comment which had already been realized
quite some time ago.

[ Impact: allow explicit percpu first chunk allocator selection ]
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reported-by: default avatarJan Beulich <JBeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
      fa8a7094
    • Tejun Heo's avatar
      x86: fix pageattr handling for lpage percpu allocator and re-enable it · e59a1bb2
      Tejun Heo authored 
      lpage allocator aliases a PMD page for each cpu and returns whatever
is unused to the page allocator.  When the pageattr of the recycled
pages are changed, this makes the two aliases point to the overlapping
regions with different attributes which isn't allowed and known to
cause subtle data corruption in certain cases.

This can be handled in simliar manner to the x86_64 highmap alias.
pageattr code should detect if the target pages have PMD alias and
split the PMD alias and synchronize the attributes.

pcpur allocator is updated to keep the allocated PMD pages map sorted
in ascending address order and provide pcpu_lpage_remapped() function
which binary searches the array to determine whether the given address
is aliased and if so to which address.  pageattr is updated to use
pcpu_lpage_remapped() to detect the PMD alias and split it up as
necessary from cpa_process_alias().

Jan Beulich spotted the original problem and incorrect usage of vaddr
instead of laddr for lookup.

With this, lpage percpu allocator should work correctly.  Re-enable
it.

[ Impact: fix subtle lpage pageattr bug and re-enable lpage ]
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reported-by: default avatarJan Beulich <JBeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
      e59a1bb2
    • Tejun Heo's avatar
      x86: reorganize cpa_process_alias() · 992f4c1c
      Tejun Heo authored 
      Reorganize cpa_process_alias() so that new alias condition can be
added easily.

Jan Beulich spotted problem in the original cleanup thread which
incorrectly assumed the two existing conditions were mutially
exclusive.

[ Impact: code reorganization ]
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
      992f4c1c
    • Tejun Heo's avatar
      x86: prepare setup_pcpu_lpage() for pageattr fix · 0ff2587f
      Tejun Heo authored 
      Make the following changes in preparation of coming pageattr updates.

* Define and use array of struct pcpul_ent instead of array of
  pointers.  The only difference is ->cpu field which is set but
  unused yet.

* Rename variables according to the above change.

* Rename local variable vm to pcpul_vm and move it out of the
  function.

[ Impact: no functional difference ]
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
      0ff2587f
    • Tejun Heo's avatar
      x86: rename remap percpu first chunk allocator to lpage · 97c9bf06
      Tejun Heo authored 
      The "remap" allocator remaps large pages to build the first chunk;
however, the name isn't very good because 4k allocator remaps too and
the whole point of the remap allocator is using large page mapping.
The allocator will be generalized and exported outside of x86, rename
it to lpage before that happens.

percpu_alloc kernel parameter is updated to accept both "remap" and
"lpage" for lpage allocator.

[ Impact: code cleanup, kernel parameter argument updated ]
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
      97c9bf06
    • Tejun Heo's avatar
      x86: fix duplicate free in setup_pcpu_remap() failure path · c5806df9
      Tejun Heo authored 
      In the failure path, setup_pcpu_remap() tries to free the area which
has already been freed to make holes in the large page.  Fix it.

[ Impact: fix duplicate free in failure path ]
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
      c5806df9
    • Tejun Heo's avatar
      percpu: fix too lazy vunmap cache flushing · 85ae87c1
      Tejun Heo authored 
      In pcpu_unmap(), flushing virtual cache on vunmap can't be delayed as
the page is going to be returned to the page allocator.  Only TLB
flushing can be put off such that vmalloc code can handle it lazily.
Fix it.

[ Impact: fix subtle virtual cache flush bug ]
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
      85ae87c1
  9. 21 Jun, 2009 23 commits
  11. 20 Jun, 2009 3 commits
    • Johannes Weiner's avatar
      mm: page_alloc: clear PG_locked before checking flags on free · c277331d
      Johannes Weiner authored 
      da456f14 "page allocator: do not disable interrupts in free_page_mlock()" moved
the PG_mlocked clearing after the flag sanity checking which makes mlocked
pages always trigger 'bad page'.  Fix this by clearing the bit up front.
Reported--and-debugged-by: default avatarPeter Chubb <peter.chubb@nicta.com.au>
Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarMel Gorman <mel@csn.ul.ie>
Tested-by: default avatarMaxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c277331d
    • Linus Torvalds's avatar
      x86, 64-bit: Clean up user address masking · 9063c61f
      Linus Torvalds authored 
      The discussion about using "access_ok()" in get_user_pages_fast() (see
commit 7f818906: "x86: don't use
'access_ok()' as a range check in get_user_pages_fast()" for details and
end result), made us notice that x86-64 was really being very sloppy
about virtual address checking.

So be way more careful and straightforward about masking x86-64 virtual
addresses:

 - All the VIRTUAL_MASK* variants now cover half of the address
   space, it's not like we can use the full mask on a signed
   integer, and the larger mask just invites mistakes when
   applying it to either half of the 48-bit address space.

 - /proc/kcore's kc_offset_to_vaddr() becomes a lot more
   obvious when it transforms a file offset into a
   (kernel-half) virtual address.

 - Unify/simplify the 32-bit and 64-bit USER_DS definition to
   be based on TASK_SIZE_MAX.

This cleanup and more careful/obvious user virtual address checking also
uncovered a buglet in the x86-64 implementation of strnlen_user(): it
would do an "access_ok()" check on the whole potential area, even if the
string itself was much shorter, and thus return an error even for valid
strings. Our sloppy checking had hidden this.

So this fixes 'strnlen_user()' to do this properly, the same way we
already handled user strings in 'strncpy_from_user()'.  Namely by just
checking the first byte, and then relying on fault handling for the
rest.  That always works, since we impose a guard page that cannot be
mapped at the end of the user space address space (and even if we
didn't, we'd have the address space hole).
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9063c61f
    • Linus Torvalds's avatar
      Merge branch 'irq-fixes-for-linus' of... · 2453d6ff
      Linus Torvalds authored 
      Merge branch 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  genirq, irq.h: Fix kernel-doc warnings
  genirq: fix comment to say IRQ_WAKE_THREAD
      2453d6ff
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