Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

To: Sergey Senozhatsky <sergey.senozhatsky.work@xxxxxxxxx>
Subject: Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
From: Sergey Senozhatsky <sergey.senozhatsky.work@xxxxxxxxx>
Date: Tue, 23 Jan 2018 16:31:43 +0900
Cc: Petr Mladek <pmladek@xxxxxxxx>, Tejun Heo <tj@xxxxxxxxxx>, Steven Rostedt <rostedt@xxxxxxxxxxx>, akpm@xxxxxxxxxxxxxxxxxxxx, linux-mm@xxxxxxxxx, Cong Wang <xiyou.wangcong@xxxxxxxxx>, Dave Hansen <dave.hansen@xxxxxxxxx>, Johannes Weiner <hannes@xxxxxxxxxxx>, Mel Gorman <mgorman@xxxxxxx>, Michal Hocko <mhocko@xxxxxxxxxx>, Vlastimil Babka <vbabka@xxxxxxx>, Peter Zijlstra <peterz@xxxxxxxxxxxxx>, Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>, Jan Kara <jack@xxxxxxx>, Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>, Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>, rostedt@xxxxxxxxxxxxxxxxxxxxx, Byungchul Park <byungchul.park@xxxxxxx>, Pavel Machek <pavel@xxxxxx>, linux-kernel@xxxxxxxxxxxxxxx, Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
In-reply-to: <20180123064023.GA492@jagdpanzerIV>
References: <20180116194456.GS3460072@devbig577.frc2.facebook.com> <20180117091208.ezvuhumnsarz5thh@pathway.suse.cz> <20180117151509.GT3460072@devbig577.frc2.facebook.com> <20180117121251.7283a56e@gandalf.local.home> <20180117134201.0a9cbbbf@gandalf.local.home> <20180119132052.02b89626@gandalf.local.home> <20180120071402.GB8371@jagdpanzerIV> <20180120104931.1942483e@gandalf.local.home> <20180121141521.GA429@tigerII.localdomain> <20180123064023.GA492@jagdpanzerIV>
User-agent: Mutt/1.9.2 (2017-12-15)

On (01/23/18 15:40), Sergey Senozhatsky wrote:
> 
> Why do we even use irq_work for printk_safe?
> 

... perhaps because of

wq: pool->lock -> printk -> call_console_drivers -> printk -> vprintk_safe -> wq: pool->lock

Which is a "many things have gone wrong" type of scenario. Maybe we
can workaround it somehow, hm. Tejun, can we have lockless WQ? ;)

	-ss

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>

References:
- Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
  - From: Tejun Heo
- Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
  - From: Petr Mladek
- Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
  - From: Tejun Heo
- Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
  - From: Steven Rostedt
- Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
  - From: Steven Rostedt
- Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
  - From: Steven Rostedt
- Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
  - From: Sergey Senozhatsky
- Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
  - From: Steven Rostedt
- Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
  - From: Sergey Senozhatsky
- Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
  - From: Sergey Senozhatsky

Prev by Date: Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
Next by Date: Re: [PATCH] mm,oom: Don't call schedule_timeout_killable() with oom_lock held.
Previous by thread: Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
Next by thread: Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
Index(es):
- Date
- Thread

[Index of Archives] [Linux ARM Kernel] [Linux ARM] [Linux Omap] [Fedora ARM] [IETF Annouce] [Bugtraq] [Linux OMAP] [Linux MIPS] [eCos] [Asterisk Internet PBX] [Linux API]