Messages in this thread Patch in this message | | | Date | Thu, 23 Feb 2006 14:11:10 -0800 (PST) | From | Christoph Lameter <> | Subject | time_interpolator: Use readq_relaxed() instead of readq(). |
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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.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Index: linux-2.6.16-rc4/kernel/timer.c =================================================================== --- linux-2.6.16-rc4.orig/kernel/timer.c 2006-02-17 14:23:45.000000000 -0800 +++ linux-2.6.16-rc4/kernel/timer.c 2006-02-23 14:03:02.000000000 -0800 @@ -1351,10 +1351,10 @@ static inline u64 time_interpolator_get_ 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(); } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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