From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Maninder Singh <maninder1.s@samsung.com>,
sergey.senozhatsky@gmail.com, rostedt@goodmis.org,
linux-kernel@vger.kernel.org, a.sahrawat@samsung.com,
pankaj.m@samsung.com, v.narang@samsung.com
Subject: Re: [PATCH 2/2] printk: make sure to print log on console.
Date: Fri, 1 Jun 2018 18:37:38 +0900 [thread overview]
Message-ID: <20180601093738.GC1841@jagdpanzerIV> (raw)
In-Reply-To: <20180601090942.ek3j4bpbhschljrw@pathway.suse.cz>
On (06/01/18 11:09), Petr Mladek wrote:
> > [...]
> >
> > > So I'd say that most likely the following scenarios can suffer:
> > >
> > > - NMI comes in, sets loglevel to X, printk-s some data, restores the
> > > loglevel back to Y
> > > - IRQ comes in [like sysrq, etc] comes in and does the same thing
> > > - software exception comes in and does the same thing [e.g. bust_spinlocks()
> > > at arch/s390/mm/fault.c]
>
> I forgot to say that it was a great point and analyze.
Thanks :)
> > My view is:
> >
> > The race with another printk() (console_lock owner) is much more
> > likely than a race between two CPUs manipulating console_loglevel.
> >
> > The proposed patch seems to be in the right direction. It is supposed
> > to fix the most likely scenario. We could block it and request full
> > solution but I wonder if it is worth it.
> >
> > I am personally fine with this partial solution for now. We could
> > always make it better if people meet the other scenarios.
>
> I am still fine with the partial solution. Well, I will think
> more about it before approving any patch.
Same here. I don't mind the patch and can agree with this partial
solution [may be we are missing more cases?]. Probably will need
a little bit more time.
-ss
next prev parent reply other threads:[~2018-06-01 9:37 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20180531102246epcas5p2f1cbc6ff217172e12e2f78bb88eb4a7e@epcas5p2.samsung.com>
2018-05-31 10:19 ` [PATCH 2/2] printk: make sure to print log on console Maninder Singh
2018-05-31 10:52 ` Sergey Senozhatsky
2018-05-31 12:21 ` Petr Mladek
2018-06-01 4:40 ` Sergey Senozhatsky
2018-06-01 8:53 ` Petr Mladek
2018-06-01 9:09 ` Petr Mladek
2018-06-01 9:37 ` Sergey Senozhatsky [this message]
2018-06-01 9:18 ` Sergey Senozhatsky
[not found] ` <CGME20180531102246epcas5p2f1cbc6ff217172e12e2f78bb88eb4a7e@epcms5p5>
2018-06-01 8:42 ` Vaneet Narang
2018-06-01 9:34 ` Sergey Senozhatsky
2018-05-31 13:27 ` Petr Mladek
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