linux-kernel - Re: [PATCH] detour TTY driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sat, 26 Jun 2010 03:48:31 +0200
From:	Samo Pogacnik <samo_pogacnik@....net>
To:	Alan Cox <alan@...rguk.ukuu.org.uk>
Cc:	linux-embedded <linux-embedded@...r.kernel.org>,
	linux kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] detour TTY driver - now ttyprintk

> > +static int tpk_write_room(struct tty_struct *tty)
> > +{
> > +	int ret = tpk_space;
> > +
> > +	/* allow char by char under max pressure */
> > +	if (tpk_space == 0)
> > +		tpk_space = 1;
> 
> That won't do what you think, the ldisc will keep seeing progress and
> generate millions of 1 byte I/Os in a loop !

I thought that this would automatically reduce processor load, which is
obviously not the case. Sorry for the delay, but i am trying to figure
out how to slow down write method when under pressure.

And that setting tpk_space to 1 would then be just in case we reach 0 to
enable further processing.

Samo


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/