The new intel_powerclamp thermal cooling device driver was merged in
commit 2af78448ff (Pull thermal management updates from Zhang Rui)
without any data conflicts. But there was a more subtle conflict I
missed: the driver uses MAX_USER_RT_PRIO, but commit 8bd75c77b7
("sched/rt: Move rt specific bits into new header file") had moved that
define from <linux/sched.h> to <linux/sched/rt.h>.
Which caused this build failure:
drivers/thermal/intel_powerclamp.c: In function ‘clamp_thread’:
drivers/thermal/intel_powerclamp.c:360:21: error: ‘MAX_USER_RT_PRIO’ undeclared (first use in this function)
drivers/thermal/intel_powerclamp.c:360:21: note: each undeclared identifier is reported only once for each function it appears in
And because I don't do a full "make allmodconfig" build after each pull,
I didn't notice until too late. So now the fix is here, separately from
the merge commit.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This value has already been clamped correctly to 0 through 49 in
powerclamp_set_cur_state() so this patch doesn't actually change
anything. But we should fix it anyway for consistency.
set_target_ratio is used as an offset into an array with
MAX_TARGET_RATIO (50) elements.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Intel PowerClamp driver performs synchronized idle injection across
all online CPUs. The goal is to maintain a given package level C-state
ratio.
Compared to other throttling methods already exist in the kernel,
such as ACPI PAD (taking CPUs offline) and clock modulation, this is often
more efficient in terms of performance per watt.
Please refer to Documentation/thermal/intel_powerclamp.txt for more details.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Linus Torvalds
Dan Carpenter
Jacob Pan