linux/Documentation/cpu-freq
Gautham R. Shenoy f7bc9b209e cpufreq: stats: Handle the case when trans_table goes beyond PAGE_SIZE
On platforms with large number of Pstates, the transition table, which
is a NxN matrix, can overflow beyond the PAGE_SIZE boundary.

This can be seen on POWER9 which has 100+ Pstates.

As a result, each time the trans_table is read for any of the CPUs, we
will get the following error.

---------------------------------------------------
fill_read_buffer: show+0x0/0xa0 returned bad count
---------------------------------------------------

This patch ensures that in case of an overflow, we print a warning
once in the dmesg and return FILE TOO LARGE error for this and all
subsequent accesses of trans_table.

Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-11-08 23:41:25 +01:00
..
amd-powernow.txt
core.txt cpufreq: Documentation: Updates based on current code 2017-02-03 23:59:40 +01:00
cpu-drivers.txt Documentation: cpu-freq: cpu-drivers: Fix repetition of word 'to' 2017-03-09 02:43:34 -07:00
cpufreq-nforce2.txt Fix typos in /Documentation : Misc 2006-11-30 05:21:10 +01:00
cpufreq-stats.txt cpufreq: stats: Handle the case when trans_table goes beyond PAGE_SIZE 2017-11-08 23:41:25 +01:00
index.txt cpufreq: docs: Drop intel-pstate.txt from index.txt 2017-09-28 02:08:43 +02:00
pcc-cpufreq.txt Revert "cpufreq: pcc-cpufreq: update default value of cpuinfo_transition_latency" 2016-07-22 23:51:06 +02:00