Re: 4.14 backport request for dbdda842fe96f: "printk: Add console owner and waiter logic to load balance console writes"

From: Sasha Levin
Date: Thu Dec 13 2018 - 09:29:32 EST


On Thu, Dec 13, 2018 at 10:59:31AM +0100, Petr Mladek wrote:
On Wed 2018-12-12 18:39:42, Daniel Wang wrote:
> Additionally, for dbdda842fe96f to work as expected we really
need fd5f7cde1b85d4c. Otherwise printk() can schedule under
console_sem and console_owner, which will deactivate the "load
balance" logic.

It looks like fd5f7cde1b85d4c got into 4.14.82 that was released last month.

On Wed, Dec 12, 2018 at 6:27 PM Sergey Senozhatsky
<sergey.senozhatsky.work@xxxxxxxxx> wrote:
>
> On (12/12/18 16:40), Daniel Wang wrote:
> > In case this was buried in previous messages, the commit I'd like to
> > get backported to 4.14 is dbdda842fe96f: printk: Add console owner and
> > waiter logic to load balance console writes. But another followup
> > patch that fixes a bug in that patch is also required. That is
> > c14376de3a1b: printk: Wake klogd when passing console_lock owner.
>
> Additionally, for dbdda842fe96f to work as expected we really
> need fd5f7cde1b85d4c. Otherwise printk() can schedule under
> console_sem and console_owner, which will deactivate the "load
> balance" logic.

To make it clear. Please, make sure that the following commits are
backported together:

+ dbdda842fe96f8932ba ("printk: Add console owner and waiter
logic to load balance console writes")
+ c162d5b4338d72deed6 ("printk: Hide console waiter logic into
helpers")
+ fd5f7cde1b85d4c8e09 ("printk: Never set console_may_schedule
in console_trylock()")
+ c14376de3a1befa70d9 ("printk: Wake klogd when passing
console_lock owner")


I generated this list from git log using "Fixes:" tag. It seems
to mention all commits dicussed above.

All 4 queued for 4.14, thank you.

--
Thanks,
Sasha