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author | Ingo Molnar <mingo@elte.hu> | 2006-12-30 00:48:13 (GMT) |
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committer | Linus Torvalds <torvalds@woody.osdl.org> | 2006-12-30 18:56:41 (GMT) |
commit | 9414232fa0cc28e2f51b8c76d260f2748f7953fc (patch) | |
tree | 71717c2907f4fe2f50aba355e8cf03f3a2a8b385 /drivers/macintosh | |
parent | d449db98d5d7d90f29f9f6e091b0e1d996184df1 (diff) | |
download | linux-fsl-qoriq-9414232fa0cc28e2f51b8c76d260f2748f7953fc.tar.xz |
[PATCH] sched: fix cond_resched_softirq() offset
Remove the __resched_legal() check: it is conceptually broken. The biggest
problem it had is that it can mask buggy cond_resched() calls. A
cond_resched() call is only legal if we are not in an atomic context, with
two narrow exceptions:
- if the system is booting
- a reacquire_kernel_lock() down() done while PREEMPT_ACTIVE is set
But __resched_legal() hid this and just silently returned whenever
these primitives were called from invalid contexts. (Same goes for
cond_resched_locked() and cond_resched_softirq()).
Furthermore, the __legal_resched(0) call was buggy in that it caused
unnecessarily long softirq latencies via cond_resched_softirq(). (which is
only called from softirq-off sections, hence the code did nothing.)
The fix is to resurrect the efficiency of the might_sleep checks and to
only allow the narrow exceptions.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/macintosh')
0 files changed, 0 insertions, 0 deletions