From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: sergey.senozhatsky@gmail.com
Cc: mhocko@suse.com, linux-mm@kvack.org, pmladek@suse.cz
Subject: Re: [PATCH] mm/page_alloc: Wait for oom_lock before retrying.
Date: Mon, 26 Dec 2016 19:54:30 +0900 [thread overview]
Message-ID: <201612261954.FJE69201.OFLVtFJSQFOHMO@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <20161222140930.GF413@tigerII.localdomain>
Sergey Senozhatsky wrote:
> On (12/22/16 23:01), Tetsuo Handa wrote:
> > > On (12/22/16 19:27), Tetsuo Handa wrote:
> > > > Thank you. I tried "[PATCHv6 0/7] printk: use printk_safe to handle printk()
> > > > recursive calls" at https://lkml.org/lkml/2016/12/21/232 on top of linux.git
> > > > as of commit 52bce91165e5f2db "splice: reinstate SIGPIPE/EPIPE handling", but
> > > > it turned out that your patch set does not solve this problem.
> > > >
> > > > I was assuming that sending to consoles from printk() is offloaded to a kernel
> > > > thread dedicated for that purpose, but your patch set does not do it.
> > >
> > > sorry, seems that I didn't deliver the information properly.
> > >
> > > https://gitlab.com/senozhatsky/linux-next-ss/commits/printk-safe-deferred
> > >
> > > there are 2 patch sets. the first one is printk-safe. the second one
> > > is async printk.
> > >
> > > 9 patches in total (as of now).
> > >
> > > can you access it?
> >
> > "404 The page you're looking for could not be found."
> >
> > Anonymous access not supported?
>
> oops... hm, dunno, it says
>
> : Visibility Level (?)
> :
> : Public
> : The project can be cloned without any authentication.
>
> I'll switch to github then may be.
>
> attached 9 patches.
>
> NOTE: not the final version.
>
>
> -ss
I tried these 9 patches. Generally OK.
Although there is still "schedule_timeout_killable() lockup with oom_lock held"
problem, async-printk patches help avoiding "printk() lockup with oom_lock held"
problem. Thank you.
Three comments from me.
(1) Messages from e.g. SysRq-b is not waited for sent to consoles.
"SysRq : Resetting" line is needed as a note that I gave up waiting.
(2) Messages from e.g. SysRq-t should be sent to consoles synchronously?
"echo t > /proc/sysrq-trigger" case can use asynchronous printing.
But since ALT-SysRq-T sequence from keyboard may be used when scheduler
is not responding, it might be better to use synchronous printing.
(Or define a magic key sequence to toggle synchronous/asynchronous?)
(3) I got below warning. (Though not reproducible.)
If fb_flashcursor() called console_trylock(), console_may_schedule is set to 1?
----------------------------------------
[ OK [ 255.862188] audit: type=1131 audit(1482733112.662:148): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-tmpfiles-setup-dev comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
] Stopped Create Static Device Nodes in /dev.
[ 255.871468] BUG: sleeping function called from invalid context at kernel/printk/printk.c:2325
[ 255.871469] in_atomic(): 1, irqs_disabled(): 1, pid: 10079, name: plymouthd
[ 255.871469] 6 locks held by plymouthd/10079:
[ 255.871470] #0: (&tty->ldisc_sem){++++.+}, at: [<ffffffff817413e2>] ldsem_down_read+0x32/0x40
[ 255.871472] #1: (&tty->atomic_write_lock){+.+.+.}, at: [<ffffffff81424309>] tty_write_lock+0x19/0x50
[ 255.871474] #2: (&tty->termios_rwsem){++++..}, at: [<ffffffff81429d59>] n_tty_write+0x99/0x470
[ 255.871475] #3: (&ldata->output_lock){+.+...}, at: [<ffffffff81429df0>] n_tty_write+0x130/0x470
[ 255.871477] #4: (console_lock){+.+.+.}, at: [<ffffffff8110616e>] console_unlock+0x33e/0x6b0
[ 255.871479] #5: (printing_lock){......}, at: [<ffffffff8143baf5>] vt_console_print+0x75/0x3d0
[ 255.871481] irq event stamp: 15244
[ 255.871481] hardirqs last enabled at (15243): [<ffffffff81105011>] __down_trylock_console_sem+0x91/0xa0
[ 255.871482] hardirqs last disabled at (15244): [<ffffffff81105ea4>] console_unlock+0x74/0x6b0
[ 255.871482] softirqs last enabled at (14968): [<ffffffff81096394>] __do_softirq+0x344/0x580
[ 255.871482] softirqs last disabled at (14963): [<ffffffff810968d3>] irq_exit+0xe3/0x120
[ 255.871483] CPU: 0 PID: 10079 Comm: plymouthd Not tainted 4.9.0-next-20161224+ #12
[ 255.871483] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013
[ 255.871484] Call Trace:
[ 255.871484] dump_stack+0x85/0xc9
[ 255.871485] ___might_sleep+0x14a/0x250
[ 255.871485] console_conditional_schedule+0x22/0x30
[ 255.871485] fbcon_redraw.isra.24+0xa3/0x1d0
[ 255.871486] ? fbcon_cursor+0x151/0x1c0
[ 255.871486] fbcon_scroll+0x11d/0xcb0
[ 255.871487] con_scroll+0x160/0x170
[ 255.871487] lf+0x9c/0xb0
[ 255.871487] vt_console_print+0x2b7/0x3d0
[ 255.871488] console_unlock+0x457/0x6b0
[ 255.871488] do_con_write.part.19+0x737/0x9e0
[ 255.871489] ? mark_held_locks+0x71/0x90
[ 255.871489] con_write+0x57/0x60
[ 255.871489] n_tty_write+0x1bf/0x470
[ 255.871490] ? prepare_to_wait_event+0x110/0x110
[ 255.871490] tty_write+0x157/0x2d0
[ 255.871491] ? n_tty_open+0xd0/0xd0
[ 255.871491] __vfs_write+0x32/0x140
[ 255.871491] ? trace_hardirqs_on+0xd/0x10
[ 255.871492] ? __audit_syscall_entry+0xaa/0xf0
[ 255.871492] vfs_write+0xc2/0x1f0
[ 255.871493] ? syscall_trace_enter+0x1cb/0x3e0
[ 255.871493] SyS_write+0x53/0xc0
[ 255.871493] do_syscall_64+0x67/0x1f0
[ 255.871494] entry_SYSCALL64_slow_path+0x25/0x25
[ 255.871494] RIP: 0033:0x7fb74cf8fc60
[ 255.871495] RSP: 002b:00007ffcaab3fe88 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 255.871495] RAX: ffffffffffffffda RBX: 000055d3acaf7160 RCX: 00007fb74cf8fc60
[ 255.871496] RDX: 000000000000003f RSI: 000055d3acafd090 RDI: 0000000000000009
[ 255.871496] RBP: 000055d3acafc440 R08: 0000000000000070 R09: 0000000000000000
[ 255.871497] R10: 000000000000003f R11: 0000000000000246 R12: 000055d3acafc330
[ 255.871497] R13: 000000000000003f R14: 00007ffcaab3ffb0 R15: 0000000000000000
Stopping Create Static Device Nodes in /dev...
----------------------------------------
# ./scripts/faddr2line vmlinux console_unlock+0x74/0x6b0
console_unlock+0x74/0x6b0:
console_unlock at kernel/printk/printk.c:2228
# ./scripts/faddr2line vmlinux console_unlock+0x457/0x6b0
console_unlock+0x457/0x6b0:
call_console_drivers at kernel/printk/printk.c:1613
(inlined by) console_unlock at kernel/printk/printk.c:2277
# ./scripts/faddr2line vmlinux vt_console_print+0x2b7/0x3d0
vt_console_print+0x2b7/0x3d0:
cr at drivers/tty/vt/vt.c:1137
(inlined by) vt_console_print at drivers/tty/vt/vt.c:2598
# ./scripts/faddr2line vmlinux lf+0x9c/0xb0
lf+0x9c/0xb0:
lf at drivers/tty/vt/vt.c:1112
# ./scripts/faddr2line vmlinux con_scroll+0x160/0x170
con_scroll+0x160/0x170:
con_scroll at drivers/tty/vt/vt.c:327 (discriminator 1)
# ./scripts/faddr2line vmlinux fbcon_scroll+0x11d/0xcb0
fbcon_scroll+0x11d/0xcb0:
fbcon_scroll at drivers/video/console/fbcon.c:1898
# ./scripts/faddr2line vmlinux fbcon_cursor+0x151/0x1c0
fbcon_cursor+0x151/0x1c0:
fbcon_cursor at drivers/video/console/fbcon.c:1331
# ./scripts/faddr2line vmlinux fbcon_redraw.isra.24+0xa3/0x1d0
fbcon_redraw.isra.24+0xa3/0x1d0:
fbcon_redraw at drivers/video/console/fbcon.c:1756
# ./scripts/faddr2line vmlinux console_conditional_schedule+0x22/0x30
console_conditional_schedule+0x22/0x30:
console_conditional_schedule at kernel/printk/printk.c:2325
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2016-12-26 10:54 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-06 10:33 Tetsuo Handa
2016-12-07 8:15 ` Michal Hocko
2016-12-07 15:29 ` Tetsuo Handa
2016-12-08 8:20 ` Vlastimil Babka
2016-12-08 11:00 ` Tetsuo Handa
2016-12-08 13:32 ` Michal Hocko
2016-12-08 16:18 ` Sergey Senozhatsky
2016-12-08 13:27 ` Michal Hocko
2016-12-09 14:23 ` Tetsuo Handa
2016-12-09 14:46 ` Michal Hocko
2016-12-10 11:24 ` Tetsuo Handa
2016-12-12 9:07 ` Michal Hocko
2016-12-12 11:49 ` Petr Mladek
2016-12-12 13:00 ` Michal Hocko
2016-12-12 14:05 ` Tetsuo Handa
2016-12-13 1:06 ` Sergey Senozhatsky
2016-12-12 12:12 ` Tetsuo Handa
2016-12-12 12:55 ` Michal Hocko
2016-12-12 13:19 ` Michal Hocko
2016-12-13 12:06 ` Tetsuo Handa
2016-12-13 17:06 ` Michal Hocko
2016-12-14 11:37 ` Tetsuo Handa
2016-12-14 12:42 ` Michal Hocko
2016-12-14 16:36 ` Tetsuo Handa
2016-12-14 18:18 ` Michal Hocko
2016-12-15 10:21 ` Tetsuo Handa
2016-12-19 11:25 ` Tetsuo Handa
2016-12-19 12:27 ` Sergey Senozhatsky
2016-12-20 15:39 ` Sergey Senozhatsky
2016-12-22 10:27 ` Tetsuo Handa
2016-12-22 10:53 ` Petr Mladek
2016-12-22 13:40 ` Sergey Senozhatsky
2016-12-22 13:33 ` Tetsuo Handa
2016-12-22 19:24 ` Michal Hocko
2016-12-24 6:25 ` Tetsuo Handa
2016-12-26 11:49 ` Michal Hocko
2016-12-27 10:39 ` Tetsuo Handa
2016-12-27 10:57 ` Michal Hocko
2016-12-22 13:42 ` Sergey Senozhatsky
2016-12-22 14:01 ` Tetsuo Handa
2016-12-22 14:09 ` Sergey Senozhatsky
2016-12-22 14:30 ` Sergey Senozhatsky
2016-12-26 10:54 ` Tetsuo Handa [this message]
2016-12-26 11:34 ` Sergey Senozhatsky
2017-01-12 13:10 ` Petr Mladek
2017-01-13 2:52 ` Sergey Senozhatsky
2017-01-13 3:53 ` Sergey Senozhatsky
2017-01-13 11:15 ` Petr Mladek
2017-01-13 11:14 ` Petr Mladek
2017-01-12 14:18 ` Petr Mladek
2017-01-13 2:28 ` Sergey Senozhatsky
2017-01-13 11:03 ` Petr Mladek
2017-01-13 11:50 ` Sergey Senozhatsky
2017-01-13 12:15 ` Petr Mladek
2016-12-26 11:41 ` Sergey Senozhatsky
2017-01-13 14:03 ` Petr Mladek
2016-12-15 1:11 ` Sergey Senozhatsky
2016-12-15 6:35 ` Michal Hocko
2016-12-15 10:16 ` Petr Mladek
2016-12-14 9:37 ` Petr Mladek
2016-12-14 10:20 ` Sergey Senozhatsky
2016-12-14 11:01 ` Petr Mladek
2016-12-14 12:23 ` Sergey Senozhatsky
2016-12-14 12:47 ` Petr Mladek
2016-12-14 10:26 ` Michal Hocko
2016-12-15 7:34 ` Sergey Senozhatsky
2016-12-14 11:37 ` Tetsuo Handa
2016-12-14 12:36 ` Petr Mladek
2016-12-14 12:44 ` Michal Hocko
2016-12-14 13:36 ` Tetsuo Handa
2016-12-14 13:52 ` Michal Hocko
2016-12-14 12:50 ` Sergey Senozhatsky
2016-12-12 14:59 ` Tetsuo Handa
2016-12-12 15:55 ` Michal Hocko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=201612261954.FJE69201.OFLVtFJSQFOHMO@I-love.SAKURA.ne.jp \
--to=penguin-kernel@i-love.sakura.ne.jp \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=pmladek@suse.cz \
--cc=sergey.senozhatsky@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox