Date: Sun, 31 Dec 1995 18:31:34 +1100 From: Bruce Evans <bde@zeta.org.au> To: hackers@freebsd.org, imb@scgt.oz.au Subject: Re: 2.1 instabilities Message-ID: <199512310731.SAA22598@godzilla.zeta.org.au>
next in thread | raw e-mail | index | archive | help
>As a consequence of (not unexpected) instabilities in -current, I reverted
>four of my machines back to -stable but I have a few niggling problems.
>Two of them occasionally stop dead whilst under heavy ppp load. Both are
>using kernel-based ppp. One of them simply stops blinking his cursor and
>simply goes to sleep. No keyboard response, nothing :-(. Very rarely, it
>will just spontaneously reboot (which I'd actually prefer as it's 4km away).
Try the following fix from -current:
---
[part of] diff -c -2 -r1.8.4.1 -r1.12
*** spl.h 1995/08/23 09:43:11 1.8.4.1
--- spl.h 1995/10/30 17:01:37 1.12
***************
*** 63,69 ****
* run while other swi handlers are running and timeout routines can call
* swi handlers. Everything includes SWI_AST_MASK so that AST's are masked
! * until just before return to user mode.
*/
! #define SWI_TTY_MASK (SWI_TTY_PENDING | SWI_CLOCK_MASK)
#define SWI_NET_MASK (SWI_NET_PENDING | SWI_CLOCK_MASK)
#define SWI_CLOCK_MASK (SWI_CLOCK_PENDING | SWI_AST_MASK)
--- 63,73 ----
* run while other swi handlers are running and timeout routines can call
* swi handlers. Everything includes SWI_AST_MASK so that AST's are masked
! * until just before return to user mode. SWI_TTY_MASK includes SWI_NET_MASK
! * in case tty interrupts are processed at splsofttty() for a tty that is in
! * SLIP or PPP line discipline (this is weaker than merging net_imask with
! * tty_imask in isa.c - splimp() must mask hard and soft tty interrupts, but
! * spltty() apparently only needs to mask soft net interrupts).
*/
! #define SWI_TTY_MASK (SWI_TTY_PENDING | SWI_CLOCK_MASK | SWI_NET_MASK)
#define SWI_NET_MASK (SWI_NET_PENDING | SWI_CLOCK_MASK)
#define SWI_CLOCK_MASK (SWI_CLOCK_PENDING | SWI_AST_MASK)
---
>The other, the only other under such a heavy load, stops forwarding IP
>packets and a ping (from the host itself) to any one of the remote users
>returns a "cannot write, no buffers available" error. The mbuf cluster count
>is <100 although there are usually somewhere around 100-300 mbufs allocated
>to data (load dependent). Killing any pppd will solve the problem until the
>next recurrence.
The fix is less likely to help here.
>...
>Switching to user-mode PPP is not an option .. each link is sufficiently
>saturated so as to cause echo packets to be lost (or delayed beyond its
>tolerance). Using it, none of them will stay connected for >15 minutes with
>the end-user's current data rates (bulk NNTP traffic yielding averages above
>3000cps).
3000 cps/line (8 lines?). That is possible but perhaps not easy for the
486DX33. These changes from -current and hsu's changes for increasing
the buffer sizes might help. These changes only affect termios mode, not
slip or ppp.
---
[part of] diff -c -2 -r1.46.2.2 -r1.78
*** tty.c 1995/11/03 08:01:04 1.46.2.2
--- tty.c 1995/12/16 21:45:02 1.78
***************
*** 216,220 ****
*/
clist_alloc_cblocks(&tp->t_canq, TTYHOG, 512);
! clist_alloc_cblocks(&tp->t_outq, TTMAXHIWAT + 200, 512);
clist_alloc_cblocks(&tp->t_rawq, TTYHOG, TTYHOG);
--- 222,227 ----
*/
clist_alloc_cblocks(&tp->t_canq, TTYHOG, 512);
! clist_alloc_cblocks(&tp->t_outq, TTMAXHIWAT + OBUFSIZ + 100,
! TTMAXHIWAT + OBUFSIZ + 100);
clist_alloc_cblocks(&tp->t_rawq, TTYHOG, TTYHOG);
***************
*** 1161,1165 ****
--- 1168,1185 ----
ttwakeup(tp);
if (ISSET(tp->t_state, TS_TBLOCK)) {
+ if (rw & FWRITE)
+ FLUSHQ(&tp->t_outq);
ttyunblock(tp);
+
+ /*
+ * Don't let leave any state that might clobber the
+ * next line discipline (although we should do more
+ * to send the START char). Not clearing the state
+ * may have caused the "putc to a clist with no
+ * reserved cblocks" panic/printf.
+ */
+ CLR(tp->t_state, TS_TBLOCK);
+
+ #if 0 /* forget it, sleeping isn't always safe and we don't know when it is */
if (ISSET(tp->t_iflag, IXOFF)) {
/*
***************
*** 1181,1184 ****
--- 1201,1205 ----
goto again;
}
+ #endif
}
}
***************
*** 1672,1676 ****
s = spltty();
oldsig = wait ? curproc->p_siglist : 0;
! if (tp->t_outq.c_cc > hiwat + 200)
while (tp->t_outq.c_cc > hiwat) {
ttstart(tp);
--- 1699,1703 ----
s = spltty();
oldsig = wait ? curproc->p_siglist : 0;
! if (tp->t_outq.c_cc > hiwat + OBUFSIZ + 100)
while (tp->t_outq.c_cc > hiwat) {
ttstart(tp);
---
Bruce
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199512310731.SAA22598>