From: Nathan Lynch <nathanl@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: aik@ozlabs.ru, ajd@linux.ibm.com, tyreld@linux.ibm.com
Subject: [RFC 00/10] powerpc/rtas: improved busy and extended delay status handling
Date: Mon, 3 May 2021 22:03:48 -0500 [thread overview]
Message-ID: <20210504030358.1715034-1-nathanl@linux.ibm.com> (raw)
This is an attempt at providing clearer names as discussed here:
https://github.com/linuxppc/issues/issues/164
as well as providing better behavior for RTAS_BUSY (-2) and small
extended delay values, which in my experience seem more common than
the larger ones. In testing PREEMPT_NONE kernels with CPUs busy, I see
the elapsed time for memory add operations roughly halved, while
memory remove operations' elapsed time shrinks by about ~25%. This is
achieved without significantly more time spent on CPU:
(- is before, + is after)
Performance counter stats for 'drmgr -c mem -a -q 10' (10 runs):
- 1,898 probe:rtas_call # 0.003 M/sec ( +- 2.20% )
- 751.57 msec task-clock # 0.289 CPUs utilized ( +- 1.56% )
+ 1,969 probe:rtas_call # 0.003 M/sec ( +- 2.69% )
+ 766.20 msec task-clock # 0.688 CPUs utilized ( +- 1.99% )
- 2.605 +- 0.148 seconds time elapsed ( +- 5.70% )
+ 1.1129 +- 0.0660 seconds time elapsed ( +- 5.93% )
Performance counter stats for 'drmgr -c mem -r -q 10' (10 runs):
- 673 probe:rtas_call # 0.002 M/sec ( +- 0.55% )
- 318.36 msec task-clock # 0.234 CPUs utilized ( +- 0.42% )
+ 692 probe:rtas_call # 0.002 M/sec ( +- 0.73% )
+ 320.87 msec task-clock # 0.309 CPUs utilized ( +- 0.34% )
- 1.362 +- 0.100 seconds time elapsed ( +- 7.37% )
+ 1.0372 +- 0.0468 seconds time elapsed ( +- 4.51% )
Questions / concerns / to do:
* I don't love the new API function names.
* Introduces three new APIs when two likely would suffice.
* Need to convert eeh_pseries and scanlog.
* rtas_busy_delay() and rtas_busy_delay_time() not yet removed.
Nathan Lynch (10):
powerpc/rtas: new APIs for busy and extended delay statuses
powerpc/rtas: do not schedule in rtas_os_term()
powerpc/rtas-rtc: convert get-time-of-day to rtas_force_spin_if_busy()
powerpc/rtas-rtc: convert set-time-of-day to rtas_sched_if_busy()
powerpc/pseries/fadump: convert to rtas_sched_if_busy()
powerpc/pseries/msi: convert to rtas_sched_if_busy()
powerpc/pseries/iommu: convert to rtas_sched_if_busy()
powerpc/pseries/dlpar: convert to rtas_sched_if_busy()
powerpc/rtas: convert to rtas_sched_if_busy()
powerpc/rtas_flash: convert to rtas_sched_if_busy()
arch/powerpc/include/asm/rtas.h | 4 +
arch/powerpc/kernel/rtas-rtc.c | 38 +---
arch/powerpc/kernel/rtas.c | 178 ++++++++++++++++++-
arch/powerpc/kernel/rtas_flash.c | 4 +-
arch/powerpc/platforms/pseries/dlpar.c | 2 +-
arch/powerpc/platforms/pseries/iommu.c | 2 +-
arch/powerpc/platforms/pseries/msi.c | 4 +-
arch/powerpc/platforms/pseries/rtas-fadump.c | 22 +--
8 files changed, 190 insertions(+), 64 deletions(-)
--
2.30.2
next reply other threads:[~2021-05-04 3:04 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-04 3:03 Nathan Lynch [this message]
2021-05-04 3:03 ` [RFC 01/10] powerpc/rtas: new APIs for busy and extended delay statuses Nathan Lynch
2021-05-13 9:59 ` Alexey Kardashevskiy
2021-05-04 3:03 ` [RFC 02/10] powerpc/rtas: do not schedule in rtas_os_term() Nathan Lynch
2021-05-04 3:03 ` [RFC 03/10] powerpc/rtas-rtc: convert get-time-of-day to rtas_force_spin_if_busy() Nathan Lynch
2021-05-04 3:03 ` [RFC 04/10] powerpc/rtas-rtc: convert set-time-of-day to rtas_sched_if_busy() Nathan Lynch
2021-05-04 3:03 ` [RFC 05/10] powerpc/pseries/fadump: convert " Nathan Lynch
2021-05-04 3:03 ` [RFC 06/10] powerpc/pseries/msi: " Nathan Lynch
2021-05-04 3:03 ` [RFC 07/10] powerpc/pseries/iommu: " Nathan Lynch
2021-05-04 3:03 ` [RFC 08/10] powerpc/pseries/dlpar: " Nathan Lynch
2021-05-04 3:03 ` [RFC 09/10] powerpc/rtas: " Nathan Lynch
2021-05-04 3:03 ` [RFC 10/10] powerpc/rtas_flash: " Nathan Lynch
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