On 4/7/20 1:47 AM, Gautham R. Shenoy wrote: > From: "Gautham R. Shenoy" <e...@linux.vnet.ibm.com> > > Hi, > > This is the fifth version of the patches to track and expose idle PURR > and SPURR ticks. These patches are required by tools such as lparstat > to compute system utilization for capacity planning purposes. > > The previous versions can be found here: > v4: https://lkml.org/lkml/2020/3/27/323 > v3: https://lkml.org/lkml/2020/3/11/331 > v2: https://lkml.org/lkml/2020/2/21/21 > v1: https://lore.kernel.org/patchwork/cover/1159341/ > > They changes from v4 are: > > - As suggested by Naveen, moved the functions read_this_idle_purr() > and read_this_idle_spurr() from Patch 2 and Patch 3 respectively > to Patch 4 where it is invoked. > > - Dropped Patch 6 which cached the values of purr, spurr, > idle_purr, idle_spurr in order to minimize the number of IPIs > sent. > > - Updated the dates for the idle_purr, idle_spurr in the > Documentation Patch 5. > > Motivation: > =========== > On PSeries LPARs, the data centers planners desire a more accurate > view of system utilization per resource such as CPU to plan the system > capacity requirements better. Such accuracy can be obtained by reading > PURR/SPURR registers for CPU resource utilization. > > Tools such as lparstat which are used to compute the utilization need > to know [S]PURR ticks when the cpu was busy or idle. The [S]PURR > counters are already exposed through sysfs. We already account for > PURR ticks when we go to idle so that we can update the VPA area. This > patchset extends support to account for SPURR ticks when idle, and > expose both via per-cpu sysfs files. > > These patches are required for enhancement to the lparstat utility > that compute the CPU utilization based on PURR and SPURR which can be > found here : > https://groups.google.com/forum/#!topic/powerpc-utils-devel/fYRo69xO9r4 > > > With the patches, when lparstat is run on a LPAR running CPU-Hogs, > ========================================================================= > sudo ./src/lparstat -E 1 3 > > System Configuration > type=Dedicated mode=Capped smt=8 lcpu=2 mem=4834112 kB cpus=0 ent=2.00 > > ---Actual--- -Normalized- > %busy %idle Frequency %busy %idle > ------ ------ ------------- ------ ------ > 1 99.99 0.00 3.35GHz[111%] 110.99 0.00 > 2 100.00 0.00 3.35GHz[111%] 111.01 0.00 > 3 100.00 0.00 3.35GHz[111%] 111.00 0.00 > > With patches, when lparstat is run on and idle LPAR > ========================================================================= > System Configuration > type=Dedicated mode=Capped smt=8 lcpu=2 mem=4834112 kB cpus=0 ent=2.00 > ---Actual--- -Normalized- > %busy %idle Frequency %busy %idle > ------ ------ ------------- ------ ------ > 1 0.15 99.84 2.17GHz[ 72%] 0.11 71.89 > 2 0.24 99.76 2.11GHz[ 70%] 0.18 69.82 > 3 0.24 99.75 2.11GHz[ 70%] 0.18 69.81 > > Gautham R. Shenoy (5): > powerpc: Move idle_loop_prolog()/epilog() functions to header file > powerpc/idle: Store PURR snapshot in a per-cpu global variable > powerpc/pseries: Account for SPURR ticks on idle CPUs > powerpc/sysfs: Show idle_purr and idle_spurr for every CPU > Documentation: Document sysfs interfaces purr, spurr, idle_purr, > idle_spurr > > Documentation/ABI/testing/sysfs-devices-system-cpu | 39 +++++++++ > arch/powerpc/include/asm/idle.h | 93 > ++++++++++++++++++++++ > arch/powerpc/kernel/sysfs.c | 82 ++++++++++++++++++- > arch/powerpc/platforms/pseries/setup.c | 8 +- > drivers/cpuidle/cpuidle-pseries.c | 39 ++------- > 5 files changed, 224 insertions(+), 37 deletions(-) > create mode 100644 arch/powerpc/include/asm/idle.h >
Reviewed-by: Tyrel Datwyler <tyr...@linux.ibm.com> Any chance this is going to be merged in the near future? There is a patchset to update lparstat in the powerpc-utils package to calculate PURR/SPURR cpu utilization that I would like to merge, but have been holding off to make sure we are synced with this proposed patchset.
