Re: CVS commit: src/sys/dev

[Ryo ONODERA <ryo%tetera.org@localhost>]

Hi,

Taylor R Campbell <campbell+netbsd-source-changes-d%mumble.net@localhost> writes:

>> Date: Tue, 04 Oct 2022 12:12:15 +0900
>> From: Ryo ONODERA <ryo%tetera.org@localhost>
>> 
>> "Taylor R Campbell" <riastradh%netbsd.org@localhost> writes:
>> 
>> > console(4), constty(4): Rip off the kernel lock.
>> 
>> After introduction of MP-safe console/constty, my kernel stopped
>> just after genfb(4) detection.
>> LOCKDEBUG, DIAGNOSTIC, DEBUG options does not provide any additional
>> information with me.
>> Could you take a look at my problem?
>
> Sorry about that -- I've reverted this change and the MP-safe cons(4)
> change for now, but let's try to figure out what's wrong with them so
> I can reapply them and get the console paths out of the kernel lock
> for good.

No problem. And thanks for your quick response.

> Can you try the attached patch on top?

With this patch, it works fine for me.
There is no stall after genfb(4).
And I do not find any other problem so far.

$ cd /usr/src
$ TZ=UTC cvs up -dP -D2022-10-04
$ patch -p1 < ~/consokfix.patch
$ ./build.sh ... kernel=...

Thank you very much!!!

> From 2de03f1efbe5b73d42dc2f59730c17b99c04b3b9 Mon Sep 17 00:00:00 2001
> From: Taylor R Campbell <riastradh%NetBSD.org@localhost>
> Date: Tue, 4 Oct 2022 05:24:49 +0000
> Subject: [PATCH] squash! constty(4): Make MP-safe.
>
> - Fix initialization of ok in cn_redirect.
> ---
>  sys/dev/cons.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/sys/dev/cons.c b/sys/dev/cons.c
> index f4f9a1602221..e621292a6b4a 100644
> --- a/sys/dev/cons.c
> +++ b/sys/dev/cons.c
> @@ -463,7 +463,7 @@ cn_redirect(dev_t *devp, int is_read, int *error, struct tty **ctpp)
>  	dev_t dev = *devp;
>  	struct tty *ctp;
>  	int s;
> -	bool ok;
> +	bool ok = false;
>  
>  	*error = ENXIO;
>  	*ctpp = NULL;
> @@ -472,18 +472,17 @@ cn_redirect(dev_t *devp, int is_read, int *error, struct tty **ctpp)
>  	    (cn_tab == NULL || (cn_tab->cn_pri != CN_REMOTE))) {
>  		if (is_read) {
>  			*error = 0;
> -			ok = false;
>  			goto out;
>  		}
>  		tty_acquire(ctp);
>  		*ctpp = ctp;
>  		dev = ctp->t_dev;
>  	} else if (cn_tab == NULL) {
> -		ok = false;
>  		goto out;
>  	} else {
>  		dev = cn_tab->cn_dev;
>  	}
> +	ok = true;
>  	*devp = dev;
>  out:	pserialize_read_exit(s);
>  	return ok;

-- 
Ryo ONODERA // ryo%tetera.org@localhost
PGP fingerprint = 82A2 DC91 76E0 A10A 8ABB  FD1B F404 27FA C7D1 15F3