From: Mike Kravetz <kravetz@us.ibm.com>
To: linux-kernel@vger.kernel.org
Subject: [RT] scheduling and oprofile
Date: Mon, 23 Oct 2006 14:23:07 -0700 [thread overview]
Message-ID: <20061023212307.GA21498@monkey.beaverton.ibm.com> (raw)
I've been trying to use oprofile on an RT kernel to look at some
performance issues. While running I notice the following sent to
the console:
BUG: scheduling with irqs disabled: java/0x00000000/4521
caller is rt_mutex_slowlock+0x156/0x1dd
[<c032051a>] schedule+0x65/0xd2 (8)
[<c0321338>] rt_mutex_slowlock+0x156/0x1dd (12)
[<c032142a>] rt_mutex_lock+0x24/0x28 (72)
[<c0134904>] rt_down_read+0x38/0x3b (20)
[<c0322a89>] do_page_fault+0xe3/0x52d (12)
[<c03229a6>] do_page_fault+0x0/0x52d (76)
[<c01033bb>] error_code+0x4f/0x54 (8)
[<c01ce6d0>] __copy_from_user_ll+0x55/0x7c (44)
[<f89be7ef>] dump_user_backtrace+0x2e/0x56 [oprofile] (24)
[<c0134869>] rt_up_read+0x3e/0x41 (20)
[<f89be864>] x86_backtrace+0x4a/0x5a [oprofile] (20)
[<f89bd53a>] oprofile_add_sample+0x73/0x89 [oprofile] (20)
[<f89beea3>] athlon_check_ctrs+0x22/0x4a [oprofile] (32)
[<f89be8c5>] nmi_callback+0x18/0x1b [oprofile] (28)
[<c01041ff>] do_nmi+0x24/0x33 (12)
[<c0103462>] nmi_stack_correct+0x1d/0x22 (16)
It seems strange to me that oprofile would be calling
'__copy_from_user_ll' in this context. I can see why the
changes made for RT locking expose this. But, doesn't this
issue also exist on non-RT (default) kernels? What happens
when we generate a page fault in this context on non-RT kernels?
--
Mike
next reply other threads:[~2006-10-23 21:22 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-10-23 21:23 Mike Kravetz [this message]
2006-10-24 2:24 ` oprofile can cause an NMI to schedule (was: [RT] scheduling and oprofile) Steven Rostedt
2006-10-24 12:46 ` John Levon
2006-10-24 12:54 ` Steven Rostedt
2006-10-25 18:58 ` Mike Kravetz
2006-10-25 19:52 ` Lee Revell
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