On Thu, 2013-02-21 at 21:56 -0800, Kevin Hilman wrote: > On 64-bit platforms, reads/writes of the various cpustat fields are > atomic due to native 64-bit loads/stores. However, on non 64-bit > platforms, reads/writes of the cpustat fields are not atomic and could > lead to inconsistent statistics.
Which is a problem how? > This problem was originally reported by Frederic Weisbecker as a > 64-bit limitation with the nsec granularity cputime accounting for > full dynticks, but then we realized that it's a problem that's been > around for awhile and not specific to the new cputime accounting. > > This series fixes this by first converting all access to the cputime > fields to use accessor functions, and then converting the accessor > functions to use the atomic64 functions. Argh!! at what cost? 64bit atomics are like expensive. Wouldn't adding a seqlock be saner? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
