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From: Dave Jones <davej@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Linux Kernel <linux-kernel@vger.kernel.org>,
	Rik van Riel <riel@redhat.com>, Ingo Molnar <mingo@redhat.com>,
	Michel Lespinasse <walken@google.com>
Subject: Re: pipe/page fault oddness.
Date: Tue, 30 Sep 2014 12:40:47 -0400	[thread overview]
Message-ID: <20140930164047.GA18354@redhat.com> (raw)
In-Reply-To: <20140930162201.GC15903@redhat.com>

On Tue, Sep 30, 2014 at 12:22:01PM -0400, Dave Jones wrote:
 
 > [<ffffffff91167913>] ? trace_graph_entry+0x123/0x250
 > [<ffffffff9115b7ce>] ? trace_buffer_lock_reserve+0x1e/0x60
 > [<ffffffff911c3c67>] ? handle_mm_fault+0x3a7/0xcd0
 > [<ffffffff910ce68d>] ? trace_hardirqs_on+0xd/0x10
 > [<ffffffff911678f8>] ? trace_graph_entry+0x108/0x250
 > [<ffffffff91042d14>] ? __do_page_fault+0x234/0x600
 > [<ffffffff9103ad23>] ? prepare_ftrace_return+0x73/0xe0
 > [<ffffffff910ca040>] ? down_write_nested+0xc0/0xc0
 > [<ffffffff910ac74d>] ? get_parent_ip+0xd/0x50
 > [<ffffffff91042d14>] ? __do_page_fault+0x234/0x600
 > [<ffffffff9103ad23>] ? prepare_ftrace_return+0x73/0xe0
 > [<ffffffff91826b3a>] ? ftrace_graph_caller+0x5a/0x85
 > [<ffffffff913a5ebe>] ? trace_hardirqs_on_thunk+0x3a/0x3f
 > [<ffffffff9118eda7>] ? context_tracking_user_exit+0x67/0x1b0
 > [<ffffffff910430fe>] ? do_page_fault+0x1e/0x70
 > [<ffffffff913a5efd>] ? trace_hardirqs_off_thunk+0x3a/0x3c
 > [<ffffffff911bd7e3>] ? copy_page_to_iter+0x3b3/0x500
 > [<ffffffff9120eddf>] ? pipe_read+0xdf/0x330
 > [<ffffffff9120ed00>] ? pipe_write+0x490/0x490
 > [<ffffffff912051a0>] ? do_sync_readv_writev+0xa0/0xa0
 > [<ffffffff912053b8>] ? do_iter_readv_writev+0x78/0xc0
 > [<ffffffff91206bbe>] ? do_readv_writev+0xce/0x280
 > [<ffffffff9120ed00>] ? pipe_write+0x490/0x490
 > [<ffffffff910cbbf6>] ? lock_release_holdtime.part.29+0xe6/0x160
 > [<ffffffff910ac74d>] ? get_parent_ip+0xd/0x50
 > [<ffffffff910ac74d>] ? get_parent_ip+0xd/0x50
 > [<ffffffff910ac8ab>] ? preempt_count_sub+0x6b/0xf0
 > [<ffffffff91206da9>] ? vfs_readv+0x39/0x50
 > [<ffffffff91206e6c>] ? SyS_readv+0x5c/0x100
 > [<ffffffff918249e4>] ? tracesys+0xdd/0xe2
 > 
 > That second one is odd, because I had disabled all the function tracing
 > before doing the sysrq-t, so still seeing all the ftrace stuff on the
 > stack suprised me.

ah, echo 0 > tracing_on isn't enough, I had to 0 out set_ftrace_pid too.
Never mind.  Subsequent traces all looking the same, minus the tracing
junk though.

Is there some way I can figure out what address it's faulting on ?
I wonder if that might give some clues.

	Dave


  reply	other threads:[~2014-09-30 16:41 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-30  3:33 pipe/page fault oddness Dave Jones
2014-09-30  4:27 ` Linus Torvalds
2014-09-30  4:33   ` Dave Jones
     [not found]     ` <CA+55aFwxdOBKHwwp7Zq1k19mHCyHYmYqigCVt59AtB-P7Zva1w@mail.gmail.com>
2014-09-30 15:52       ` Linus Torvalds
2014-09-30 16:03         ` Rik van Riel
2014-09-30 16:07           ` Dave Jones
2014-09-30 16:26           ` Linus Torvalds
2014-09-30 16:05         ` Dave Jones
2014-09-30 16:10           ` Linus Torvalds
2014-09-30 16:22             ` Dave Jones
2014-09-30 16:40               ` Dave Jones [this message]
2014-09-30 16:46                 ` Linus Torvalds
2014-09-30 18:20                   ` Dave Jones
2014-09-30 18:58                     ` Linus Torvalds
2014-10-01  8:19                       ` Hugh Dickins
2014-10-01 16:01                         ` Linus Torvalds
2014-10-01 16:18                           ` Linus Torvalds
2014-10-01 17:29                             ` Rik van Riel
2014-10-02  8:28                               ` Peter Zijlstra
2014-10-01 20:20                             ` Linus Torvalds
2014-10-01 21:09                               ` Rik van Riel
2014-10-01 22:08                               ` Sasha Levin
2014-10-01 22:28                                 ` Chuck Ebbert
2014-10-02  3:32                                   ` Sasha Levin
2014-10-02  8:03                                     ` Chuck Ebbert
2014-10-02 14:49                                       ` Sasha Levin
2014-10-01 22:42                                 ` Linus Torvalds
2014-10-02 14:25                                   ` Kirill A. Shutemov
2014-10-02 16:01                                     ` Linus Torvalds
2014-10-02 16:35                                       ` Kirill A. Shutemov
2014-10-02 15:04                                   ` Sasha Levin
2014-10-02 16:10                                     ` Linus Torvalds
2014-10-03  5:00                                       ` Sasha Levin
2014-10-03 15:43                                         ` Linus Torvalds
2014-10-03 15:58                                           ` Dave Jones
2014-10-03 16:02                                             ` Sasha Levin
2014-10-02 12:45                             ` Mel Gorman
2014-10-06 19:18                               ` Aneesh Kumar K.V
2014-10-07 12:45                                 ` Linus Torvalds
2014-10-08 10:37                                   ` Aneesh Kumar K.V
2014-10-02  8:47                           ` Hugh Dickins
2014-10-02 15:57                             ` Linus Torvalds
2014-09-30  4:35   ` Al Viro

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