Re: [GIT PULL] ring-buffer: Allow for rescheduling when removing pages
From: Greg Kroah-Hartman
Date: Wed Sep 19 2018 - 14:56:48 EST
On Wed, Sep 19, 2018 at 09:39:23AM -0400, Steven Rostedt wrote:
> On Wed, 19 Sep 2018 08:07:06 +0200
> Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> > On Tue, Sep 18, 2018 at 07:14:13PM -0400, Steven Rostedt wrote:
> > >
> > > Linus (aka Greg),
> > >
> > > Vaibhav Nagarnaik found that modifying the ring buffer size could cause
> > > a huge latency in the system because it does a while loop to free pages
> > > without releasing the CPU (on non preempt kernels). In a case where there
> > > are hundreds of thousands of pages to free it could actually cause a system
> > > stall. A properly place cond_resched() solves this issue.
> > >
> > >
> > > Please pull the latest trace-v4.19-rc4 tree, which can be found at:
> > >
> > >
> > > git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
> > > trace-v4.19-rc4
> >
> > Ick, line wrapping makes it hard to cut/paste :(
>
> ??
>
> That's the way I have always posted pull requests. I place the branch
> on the second line. It's not line wrapped, it's a hard coded new line.
> Long ago I was told to do it that way.
>
> Should that be changed? It would be trivial to update my scripts.
Ah, ok, that's not what I have been doing for a long time, nor what the
sub-maintainers that send stuff to me have done. Normally it is:
git_url tag
Like this one for perf stuff:
https://lore.kernel.org/lkml/20171027195047.27132-1-acme@xxxxxxxxxx/
If you have been doing it this way to Linus, that's fine, I can adapt :)
thanks,
greg k-h