Messages in this thread | | | Date | Wed, 15 Feb 2023 11:33:28 +0530 | From | Vishal Chourasia <> | Subject | Re: [PATCH v2] sched/debug: Put sched/domains files under the verbose flag |
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On Fri, Jan 20, 2023 at 11:33:30AM -0500, Phil Auld wrote: > The debug files under sched/domains can take a long time to regenerate, > especially when updates are done one at a time. Move these files under > the sched verbose debug flag. Allow changes to verbose to trigger > generation of the files. This lets a user batch the updates but still > have the information available. The detailed topology printk messages > are also under verbose. > > Discussion that lead to this approach can be found in the link below. > > Simplified code to maintain use of debugfs bool routines suggested by > Michael Ellerman <mpe@ellerman.id.au>. > > Signed-off-by: Phil Auld <pauld@redhat.com> > Cc: Michael Ellerman <mpe@ellerman.id.au> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Peter Zijlstra (Intel) <peterz@infradead.org> > Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> > Cc: Valentin Schneider <vschneid@redhat.com> > Cc: Vishal Chourasia <vishalc@linux.vnet.ibm.com> > Cc: Vincent Guittot <vincent.guittot@linaro.org> > Link: https://lore.kernel.org/all/Y01UWQL2y2r69sBX@li-05afa54c-330e-11b2-a85c-e3f3aa0db1e9.ibm.com/ > --- > > v2: fix comment typo and use cpumask_empty() > > kernel/sched/debug.c | 52 +++++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 49 insertions(+), 3 deletions(-)
Thanks for the Patch.
Tested-by: Vishal Chourasia <vishalc@linux.vnet.ibm.com>
Base Tag : v6.2-rc8 Patch : [V2] sched/debug: Put sched/domains files under the verbose flag
# time ppc64_cpu --smt=off | When kernel is built | with the patch, time to real 17m54.246s | smt=off is 17m54s. user 0m0.013s | sys 0m4.661s |
System Configuration:
Architecture : ppc64le CPUS : 1600 Machine : Power10 Thread per core : 8 Sockets : 15
- debug files are not created for the case where kernel command line string lacks sched_verbose parameter. - When sched_verbose is passed as kernel commandline parameter, kernel exports /sys/kernel/debug/sched/verbose file which controls creation of the debug files. + setting Y/N to this file enables/disables creation of debug files during CPU hotplug operation.
Below is the table listing time taken to perform smt=off operation under different settings.
+--------------------------+---------------+---------+------------+ | kernel | sched_verbose | verbose | time | +--------------------------+---------------+---------+------------+ | 6.2.0-rc8-patch-applied+ | YES | N | 16m58.196s | | 6.2.0-rc8-patch-applied+ | YES | Y | 33m21.774s | | 6.2.0-rc8-patch-applied+ | NO | NA | 17m54.246s | | 6.2.0-rc8 | NO | NA | 30m11.344s | +--------------------------+---------------+---------+------------+
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