Date: Tue, 1 Dec 2009 19:14:57 +0000 (UTC) From: Ed Schouten <ed@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r199998 - head/sys/kern Message-ID: <200912011914.nB1JEvV3073646@svn.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: ed Date: Tue Dec 1 19:14:57 2009 New Revision: 199998 URL: http://svn.freebsd.org/changeset/base/199998 Log: Don't allocate an input buffer for a TTY when the receiver is turned off. When the termios CREAD flag is not set, it makes little sense to allocate an input buffer. Just set the size to 0 in this case to reduce memory footprint. Disallow CREAD to be disabled for pseudo-devices to prevent foot-shooting. Modified: head/sys/kern/tty.c Modified: head/sys/kern/tty.c ============================================================================== --- head/sys/kern/tty.c Tue Dec 1 17:29:25 2009 (r199997) +++ head/sys/kern/tty.c Tue Dec 1 19:14:57 2009 (r199998) @@ -102,10 +102,11 @@ static const char *dev_console_filename; static void tty_watermarks(struct tty *tp) { - size_t bs; + size_t bs = 0; /* Provide an input buffer for 0.2 seconds of data. */ - bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX); + if (tp->t_termios.c_cflag & CREAD) + bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX); ttyinq_setsize(&tp->t_inq, tp, bs); /* Set low watermark at 10% (when 90% is available). */ @@ -890,6 +891,7 @@ ttydevsw_defparam(struct tty *tp, struct t->c_ospeed = B50; else if (t->c_ospeed > B115200) t->c_ospeed = B115200; + t->c_cflag |= CREAD; return (0); }
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200912011914.nB1JEvV3073646>