From: Mike Travis <travis@sgi.com>
To: linux-acpi@vger.kernel.org
Cc: Jack Steiner <steiner@sgi.com>, Hedi Berriche <hedi@sgi.com>,
Robin Holt <holt@sgi.com>
Subject: ACPI acpi_processor_get_throttling_info taking excessive time?
Date: Sun, 25 Apr 2010 18:47:17 -0700 [thread overview]
Message-ID: <4BD4F0A5.7050208@sgi.com> (raw)
Hi,
On our test machine that has 1664 processors, we've discovered that
the function acpi_processor_get_throttling_info takes 10 minutes.
It's estimated that with 4096 cpus, this will take over 25 minutes.
It seems that the acpi_processor_get_throttling_info serially queries
each cpu with a "runon" function to extract the throttling states.
My question is can this be optimized to use the previous processor's
throttling states? Would there be any reason to expect any of the
processors to be different?
Another thought, if each processor needs to be queried, can the
functions be run in parallel?
Each time I broke into this delay, this was the call stack:
6.559522 ( 0.000032)| Stack traceback for pid 16894
6.559554 ( 0.000032)| 0xffff8827fb4d8680 16894 1 1 358 R 0xffff8827fb4d8d10 modprobe
6.559628 ( 0.000074)| ffff8827fb535ae0 0000000000000018 ffffffff81246665 ffff8ac700000004
6.559694 ( 0.000066)| ffff8d21fc07d150 ffff8ac7fc2e8800 0000000000000000 ffff8ac7fc2e9550
6.559771 ( 0.000077)| 0000000000000000 ffff8827fb535cd8 ffffffff81235822 ffffffff8158ac76
6.559837 ( 0.000066)| Call Trace:
6.559852 ( 0.000015)| Inexact backtrace:
6.559874 ( 0.000022)|
6.559879 ( 0.000005)| [<ffffffff81246665>] ? acpi_ns_delete_namespace_by_owner+0xb2/0xdb
6.559944 ( 0.000065)| [<ffffffff81235822>] ? acpi_ds_terminate_control_method+0x74/0x102
6.560008 ( 0.000064)| [<ffffffff8124a60f>] ? acpi_ps_parse_aml+0x246/0x3c9
6.560061 ( 0.000053)| [<ffffffff81251e25>] ? acpi_ut_create_internal_object_dbg+0x18/0x79
6.560129 ( 0.000068)| [<ffffffff8124be20>] ? acpi_ps_execute_method+0x229/0x331
6.560194 ( 0.000065)| [<ffffffff81246851>] ? acpi_ns_evaluate+0x189/0x2bc
6.560246 ( 0.000052)| [<ffffffff8124611c>] ? acpi_evaluate_object+0x15e/0x2a5
6.560301 ( 0.000055)| [<ffffffff812513e8>] ? acpi_ut_update_ref_count+0x17f/0x1d6
6.560386 ( 0.000085)| [<ffffffffa012e14c>] ? acpi_processor_get_throttling_info+0x202/0x6f9 [processor]
6.560464 ( 0.000078)| [<ffffffffa0131c46>] ? acpi_processor_add+0x93a/0xa8c [processor]
6.560528 ( 0.000064)| [<ffffffff8122b247>] ? acpi_device_probe+0x4e/0x179
6.560580 ( 0.000052)| [<ffffffff8128cb28>] ? driver_probe_device+0xc8/0x2d0
6.560633 ( 0.000053)| [<ffffffff8128cdc3>] ? __driver_attach+0x93/0xa0
6.560682 ( 0.000049)| [<ffffffff8128cd30>] ? __driver_attach+0x0/0xa0
6.560740 ( 0.000058)| [<ffffffff8128c158>] ? bus_for_each_dev+0x58/0x80
6.560790 ( 0.000050)| [<ffffffff8128b945>] ? bus_add_driver+0x155/0x2b0
6.560839 ( 0.000049)| [<ffffffffa00d0000>] ? acpi_processor_init+0x0/0x10e [processor]
6.560902 ( 0.000063)| [<ffffffff8128d0d9>] ? driver_register+0x79/0x170
6.560952 ( 0.000050)| [<ffffffffa00d0000>] ? acpi_processor_init+0x0/0x10e [processor]
6.561015 ( 0.000063)| [<ffffffffa00d009a>] ? acpi_processor_init+0x9a/0x10e [processor]
6.561079 ( 0.000064)| [<ffffffff81067325>] ? __blocking_notifier_call_chain+0x65/0x90
6.561141 ( 0.000062)| [<ffffffff810001e5>] ? do_one_initcall+0x35/0x190
6.561190 ( 0.000049)| [<ffffffff8107b514>] ? sys_init_module+0xe4/0x270
6.561240 ( 0.000050)| [<ffffffff81002e7b>] ? system_call_fastpath+0x16/0x1b
Thanks,
Mike
next reply other threads:[~2010-04-26 1:47 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-26 1:47 Mike Travis [this message]
2010-04-26 2:22 ` ACPI acpi_processor_get_throttling_info taking excessive time? Zhang Rui
2010-04-26 18:14 ` Mike Travis
2010-04-27 7:05 ` Len Brown
2010-04-27 17:19 ` Mike Travis
2010-04-27 19:16 ` Mike Travis
2010-04-27 19:22 ` Mike Travis
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