On 05/19/2015 04:53 PM, Michal Hocko wrote:
On Tue 19-05-15 10:18:07, Johannes Weiner wrote:
CC'ing Tejun and cgroups for the generic cgroup interface part
On Tue, May 19, 2015 at 11:40:57AM +0100, Mel Gorman wrote:
[...]
/usr/src/linux-4.0-vanilla/mm/memcontrol.c 6.6441 395842
mem_cgroup_try_charge 2.950% 175781
Ouch. Do you have a way to get the per-instruction breakdown of this?
This function really isn't doing much. I'll try to reproduce it here
too, I haven't seen such high costs with pft in the past.
try_charge 0.150% 8928
get_mem_cgroup_from_mm 0.121% 7184
Indeed! try_charge + get_mem_cgroup_from_mm which I would expect to be
the biggest consumers here are below 10% of the mem_cgroup_try_charge.
Note that they don't explain 10% of the mem_cgroup_try_charge. They
*add* their own overhead to the overhead of mem_cgroup_try_charge
itself. Which might be what you meant but I wasn't sure.
Other than that the function doesn't do much else than some flags
queries and css_put...
Do you have the full trace?
Sorry for a stupid question but do inlines
from other header files get accounted to memcontrol.c?
Yes, perf doesn't know about them so it's accounted to function where
the code physically is.
[...]
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