On 2017.07.28 05:45 Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <[email protected]> > > After commit f8475cef9008 "x86: use common aperfmperf_khz_on_cpu() to > calculate KHz using APERF/MPERF" the scaling_cur_freq policy attribute > in sysfs only behaves as expected on x86 with APERF/MPERF registers > available when it is read from at least twice in a row. The value > returned by the first read may not be meaningful, because the > computations in there use cached values from the previous iteration > of aperfmperf_snapshot_khz() which may be stale. > > To prevent that from happening, modify arch_freq_get_on_cpu() to > call aperfmperf_snapshot_khz() twice, with a short delay between > these calls, if the previous invocation of aperfmperf_snapshot_khz() > was too far back in the past (specifically, more that 1s ago).
...[deleted the rest]... This patch seems to work fine and addresses my complaints from last week. Thanks. ... Doug
