Messages in this thread | | | Date | Mon, 5 May 2014 19:55:13 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH] printk: Remove separate printk_sched buffers and use printk buf instead |
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On Mon, 05 May 2014 16:33:51 -0700 Joe Perches <joe@perches.com> wrote:
> On Mon, 2014-05-05 at 19:18 -0400, Steven Rostedt wrote: > > To prevent deadlocks with doing a printk inside the scheduler, > > printk_sched() was created. The issue is that printk has a console_sem > > that it can grab and release. The release does a wake up if there's a > > task pending on the sem, and this wake up grabs the rq locks that is > > held in the scheduler. This leads to a possible deadlock if the wake up > > uses the same rq as the one with the rq lock held already. > [] > > kernel/printk/printk.c | 87 +++++++++++++++++++++++++++++++------------------ > [] > > @@ -2440,18 +2470,20 @@ > > #define PRINTK_BUF_SIZE 512 > > Wouldn't this define be unused and shouldn't it be deleted too? >
I guess it would.
-- Steve
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