e0e10b0607
These annotations help to mitigate false sharing on multiprocessor systems. Variables annotated with __cacheline_aligned are placed into the .data.cacheline_aligned section in the kernel. Each item in this section is aligned on a cachline boundary - this avoids false sharing. Highly contended global locks are a good candidate for __cacheline_aligned annotation. Variables annotated with __read_mostly are packed together tightly into a .data.read_mostly section in the kernel. The idea here is that we can pack infrequently modified data items into a cacheline and avoid having to purge the cache, which would happen if read mostly data and write mostly data shared a cachline. Initialisation variables are a prime candiate for __read_mostly annotations. |
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| coda | ||
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