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authorDavid S. Miller <davem@davemloft.net>2013-12-18 16:42:06 -0500
committerDavid S. Miller <davem@davemloft.net>2013-12-18 16:42:06 -0500
commit143c9054949436cb05e468439dc5e46231f33d09 (patch)
treec2e972d8188fb1b36368e9acb5b6b59466c9d903 /arch/x86/include/asm/preempt.h
parent0b6807034791160d5e584138943d2daea765436d (diff)
parent35eecf052250f663f07a4cded7d3503fd1b50729 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts: drivers/net/ethernet/intel/i40e/i40e_main.c drivers/net/macvtap.c Both minor merge hassles, simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/x86/include/asm/preempt.h')
-rw-r--r--arch/x86/include/asm/preempt.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h
index 8729723636f..c8b051933b1 100644
--- a/arch/x86/include/asm/preempt.h
+++ b/arch/x86/include/asm/preempt.h
@@ -8,6 +8,12 @@
DECLARE_PER_CPU(int, __preempt_count);
/*
+ * We use the PREEMPT_NEED_RESCHED bit as an inverted NEED_RESCHED such
+ * that a decrement hitting 0 means we can and should reschedule.
+ */
+#define PREEMPT_ENABLED (0 + PREEMPT_NEED_RESCHED)
+
+/*
* We mask the PREEMPT_NEED_RESCHED bit so as not to confuse all current users
* that think a non-zero value indicates we cannot preempt.
*/
@@ -74,6 +80,11 @@ static __always_inline void __preempt_count_sub(int val)
__this_cpu_add_4(__preempt_count, -val);
}
+/*
+ * Because we keep PREEMPT_NEED_RESCHED set when we do _not_ need to reschedule
+ * a decrement which hits zero means we have no preempt_count and should
+ * reschedule.
+ */
static __always_inline bool __preempt_count_dec_and_test(void)
{
GEN_UNARY_RMWcc("decl", __preempt_count, __percpu_arg(0), "e");