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| author | Christoph Lameter <clameter@engr.sgi.com> | 2006-03-02 02:54:35 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-02 08:33:07 -0800 |
| commit | 685db65e422bfa523b8a9dacb5a658b42b254f05 (patch) | |
| tree | 0d7eba52e7c9584a2e3b4f2cd1842bf55e67c2d0 | |
| parent | 7f99f06f01aa9460b5a18f1b0e0900c90d0a84fc (diff) | |
| download | lwn-685db65e422bfa523b8a9dacb5a658b42b254f05.tar.gz lwn-685db65e422bfa523b8a9dacb5a658b42b254f05.zip | |
[PATCH] time_interpolator: Use readq_relaxed() instead of readq().
On some platforms readq performs additional work to make sure I/O is done
in a coherent way. This is not needed for time retrieval as done by the
time interpolator. So we can use readq_relaxed instead which will improve
performance.
It affects sparc64 and ia64 only. Apparently it makes a significant
difference on ia64.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: john stultz <johnstul@us.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | kernel/timer.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/timer.c b/kernel/timer.c index fe3a9a9f8328..fc6646fd5aab 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1351,10 +1351,10 @@ static inline u64 time_interpolator_get_cycles(unsigned int src) return x(); case TIME_SOURCE_MMIO64 : - return readq((void __iomem *) time_interpolator->addr); + return readq_relaxed((void __iomem *)time_interpolator->addr); case TIME_SOURCE_MMIO32 : - return readl((void __iomem *) time_interpolator->addr); + return readl_relaxed((void __iomem *)time_interpolator->addr); default: return get_cycles(); } |