From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com,
x86@kernel.org, paulus@samba.org, mingo@elte.hu,
acme@ghostprotocols.net
Subject: Re: [PATCH 0/2 x86] fix some page faults in nmi if kmemcheck is enabled
Date: Mon, 20 Feb 2012 12:00:48 +0100 [thread overview]
Message-ID: <1329735648.2293.307.camel@twins> (raw)
In-Reply-To: <1329717665.3448.28.camel@ThinkPad-T61>
On Mon, 2012-02-20 at 14:01 +0800, Li Zhong wrote:
> If CONFIG_KMEMCHECK is enabled, there might be page faults in nmi if the
> pages are marked as not present by kmemcheck, like following:
>
> [ 4.535803] WARNING: at arch/x86/mm/kmemcheck/kmemcheck.c:634 kmemcheck_fault+0xb9/0xd0()
> [ 4.633429] Hardware name: System x3650 M3 -[7945AC1]-
> [ 4.694710] Modules linked in:
> [ 4.731105] Pid: 1, comm: swapper/0 Not tainted 3.3.0-rc3 #15
> [ 4.799654] Call Trace:
> [ 4.828751] <NMI> [<ffffffff81042eca>] warn_slowpath_common+0x7a/0xb0
> [ 4.907713] [<ffffffff81042f15>] warn_slowpath_null+0x15/0x20
> [ 4.977301] [<ffffffff8103ce89>] kmemcheck_fault+0xb9/0xd0
> [ 5.043778] [<ffffffff81551ba6>] do_page_fault+0x406/0x550
> [ 5.110252] [<ffffffff8154e235>] page_fault+0x25/0x30
> [ 5.171535] [<ffffffff8154f005>] ? nmi_handle.clone.1+0x75/0xc0
> [ 5.243202] [<ffffffff8154efcf>] ? nmi_handle.clone.1+0x3f/0xc0
> [ 5.314867] [<ffffffff8154ef90>] ? __die+0xf0/0xf0
> [ 5.373038] [<ffffffff8154f15f>] do_nmi+0x10f/0x360
> [ 5.432243] [<ffffffff8154e5cd>] restart_nmi+0x1a/0x1e
> [ 5.494565] [<ffffffff8154e210>] ? general_protection+0x30/0x30
> [ 5.566234] [<ffffffff8154e210>] ? general_protection+0x30/0x30
> [ 5.637898] [<ffffffff8154e210>] ? general_protection+0x30/0x30
> [ 5.709566] <<EOE>> [<ffffffff8126d814>] ? rb_insert_color+0xa4/0x150
> [ 5.788526] [<ffffffff8119d17b>] sysfs_link_sibling+0x8b/0x110
> [ 5.859155] [<ffffffff8119dff1>] __sysfs_add_one+0xc1/0x100
> [ 5.926666] [<ffffffff8119e056>] sysfs_add_one+0x26/0xd0
> [ 5.991065] [<ffffffff8119cdf4>] sysfs_add_file_mode+0xc4/0x100
> [ 6.062731] [<ffffffff8119fc41>] internal_create_group+0xc1/0x1a0
> [ 6.136473] [<ffffffff8119fd4e>] sysfs_create_group+0xe/0x10
> [ 6.205026] [<ffffffff81351c1a>] dpm_sysfs_add+0x2a/0xd0
> [ 6.269425] [<ffffffff81349bf5>] device_add+0x5e5/0x730
> [ 6.332783] [<ffffffff81349d59>] device_register+0x19/0x20
> [ 6.399260] [<ffffffff8135b6b8>] add_memory_section+0x158/0x1e0
> [ 6.470927] [<ffffffff81ca757e>] memory_dev_init+0x75/0x108
> [ 6.538439] [<ffffffff81ca73a9>] driver_init+0x31/0x33
> [ 6.600762] [<ffffffff81c72c68>] kernel_init+0xcc/0x169
> [ 6.664121] [<ffffffff81555e64>] kernel_thread_helper+0x4/0x10
> [ 6.734749] [<ffffffff81c72b9c>] ? start_kernel+0x3ab/0x3ab
> [ 6.802261] [<ffffffff81555e60>] ? gs_change+0x13/0x13
> [ 6.864585] ---[ end trace a7919e7f17c0a725 ]---
>
> These two patches tries to fix some of the problems by avoiding using the
> non-present pages.
Hell no, these are some of the ugliest patches I've seen in a while. Not
to mention that their changelogs are utter crap since they don't even
explain why they're doing what they're doing.
next prev parent reply other threads:[~2012-02-20 11:01 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-20 6:01 [PATCH 0/2 x86] fix some page faults in nmi if kmemcheck is enabled Li Zhong
2012-02-20 6:04 ` [PATCH 1/2 x86] fix page faults by nmi handler " Li Zhong
2012-02-20 6:07 ` [PATCH 2/2 x86] fix page faults by perf events " Li Zhong
2012-02-20 11:00 ` Peter Zijlstra [this message]
2012-02-21 1:42 ` [PATCH 0/2 x86] fix some page faults " Li Zhong
2012-02-21 10:17 ` Peter Zijlstra
2012-02-23 9:53 ` Li Zhong
2012-02-27 10:58 ` Peter Zijlstra
2012-02-28 2:45 ` Li Zhong
2012-03-02 19:44 ` Don Zickus
2012-03-05 1:49 ` Li Zhong
2012-03-05 10:05 ` [PATCH v2 x86 1/2] fix page faults by nmiaction " Li Zhong
2012-03-05 10:29 ` Wim Van Sebroeck
2012-03-06 1:46 ` Li Zhong
2012-03-05 15:54 ` Don Zickus
2012-03-05 17:55 ` Peter Zijlstra
2012-03-05 17:49 ` Peter Zijlstra
2012-03-05 21:45 ` Don Zickus
2012-03-06 10:09 ` [PATCH v3 " Li Zhong
2012-03-06 10:27 ` Vegard Nossum
2012-03-09 9:52 ` Li Zhong
2012-03-06 15:00 ` Don Zickus
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