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  1. 12 6月, 2008 1 次提交
    • J
      common implementation of iterative div/mod · f595ec96
      由 Jeremy Fitzhardinge 提交于 
      We have a few instances of the open-coded iterative div/mod loop, used
when we don't expcet the dividend to be much bigger than the divisor.
Unfortunately modern gcc's have the tendency to strength "reduce" this
into a full mod operation, which isn't necessarily any faster, and
even if it were, doesn't exist if gcc implements it in libgcc.

The workaround is to put a dummy asm statement in the loop to prevent
gcc from performing the transformation.

This patch creates a single implementation of this loop, and uses it
to replace the open-coded versions I know about.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Christian Kujau <lists@nerdbynature.de>
Cc: Robert Hancock <hancockr@shaw.ca>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      f595ec96
  3. 23 5月, 2008 1 次提交
  5. 28 4月, 2008 1 次提交
  7. 26 4月, 2008 1 次提交
  9. 25 4月, 2008 18 次提交
  11. 17 4月, 2008 4 次提交
  13. 05 4月, 2008 3 次提交
  15. 27 3月, 2008 2 次提交
    • J
      xen: fix UP setup of shared_info · 2e8fe719
      由 Jeremy Fitzhardinge 提交于 
      We need to set up the shared_info pointer once we've mapped the real
shared_info into its fixmap slot.  That needs to happen once the general
pagetable setup has been done.  Previously, the UP shared_info was set
up one in xen_start_kernel, but that was left pointing to the dummy
shared info.  Unfortunately there's no really good place to do a later
setup of the shared_info in UP, so just do it once the pagetable setup
has been done.

[ Stable: needed in 2.6.24.x ]
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      2e8fe719
    • J
      xen: fix RMW when unmasking events · 04c44a08
      由 Jeremy Fitzhardinge 提交于 
      xen_irq_enable_direct and xen_sysexit were using "andw $0x00ff,
XEN_vcpu_info_pending(vcpu)" to unmask events and test for pending ones
in one instuction.

Unfortunately, the pending flag must be modified with a locked operation
since it can be set by another CPU, and the unlocked form of this
operation was causing the pending flag to get lost, allowing the processor
to return to usermode with pending events and ultimately deadlock.

The simple fix would be to make it a locked operation, but that's rather
costly and unnecessary.  The fix here is to split the mask-clearing and
pending-testing into two instructions; the interrupt window between
them is of no concern because either way pending or new events will
be processed.

This should fix lingering bugs in using direct vcpu structure access too.

[ Stable: needed in 2.6.24.x ]
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      04c44a08
  17. 05 3月, 2008 1 次提交
  19. 01 3月, 2008 1 次提交
  21. 13 2月, 2008 1 次提交
  23. 10 2月, 2008 2 次提交
  25. 30 1月, 2008 4 次提交