be dropped when it has an unusual traffic pattern. For full details
as well as a test case that demonstrates the failure, see the
referenced PR.
Under certain circumstances involving the persist state, it is
possible for the receive side's tp->rcv_nxt to advance beyond its
tp->rcv_adv. This causes (tp->rcv_adv - tp->rcv_nxt) to become
negative. However, in the code affected by this fix, that difference
was interpreted as an unsigned number by max(). Since it was
negative, it was taken as a huge unsigned number. The effect was
to cause the receiver to believe that its receive window had negative
size, thereby rejecting all received segments including ACKs. As
the test case shows, this led to fruitless retransmissions and
eventually to a dropped connection. Even connections using the
loopback interface could be dropped. The fix substitutes the signed
imax() for the unsigned max() function.
PR: closes kern/3998
Reviewed by: davidg, fenner, wollman
because there was no non-inline spl0() to call.
Don't frob intr_nesting_level in idle() or cpu_switch(). Interrupts
are mostly disabled then, so the frobbing had little effect.
is defined, or SMP is defined. It is silly to configure PERFMON when
it can't work (it will be disabled at runtime), but I like to leave
the PERFMON configuration alone when I temporarily disable support for
modern CPUs to run regression tests.
Removed an unused #include.
- Added the psm options PSM_HOOKAPM and PSM_RESETAFTERSUSPEND.
LINT:
- Added the psm options PSM_HOOKAPM and PSM_RESETAFTERSUSPEND.
- Added comments on the flag 0x20 for syscons.
- Clarified descriptions on the flags (0x02, 0x04) regarding the cursor
shape in syscons.
cursor (CHAR_CURSOR)
1. Reduced the number of calls to set_destructive_cursor(). The
destructive cursor produced noticeable overhead on the system. It was
caused by draw_cursor_image() calling set_destructive_cursor() every
so often.
set_destructive_cursor() absolutely needs to be called when
a) the character code under the cursor has changed either because
the cursor moved or because the screen was updated or the mouse
pointer overlapped the cursor.
b) Or a new font has been loaded,
c) or the video mode has been changed,
d) or the cursor shape has been changed,
e) or the user switched virtual consoles.
2. Turn off the configuration flag CHAR_CURSOR (destructive cursor) in
scattach() if we have a non-VGA card. The destructive cursor works
only for VGA.
3. Removed redundant calls to set_destructive_cursor() in some places.
4. Fixed the "disappearing mouse pointer" problem. The mouse pointer
looked hidden under the destructive cursor when it overlaped the cursor.
A slightly different version of the patch was reviewd and OKed by
sos and ache.
reference to the programming manual. Use this near-copy of the version
of hsuser.texinfo in contrib/libreadline instead of the stale near-copy
in contrib/gdb.
If the configuration option PSM_HOOKAPM is defined and the APM device
is available, the psm driver will issue the ENABLE command to the
pointing device at the resume APM event if the device was open when
the system went into suspended mode. If the option
PSM_RESETAFTERSUSPEND is specified in addition to PSM_HOOKAPM, the
driver will try to reset the pointing device before sending the
ENABLE command.
Built-in PS/2-type pointing devices in some laptops (all the reports I
heard were about Toshiba models) sometimes don't work immediately
after the system is resumed. The device MAY become available after a
while. The system may exhibit the same symptom in other OS's too
(no, FreeBSD is not the only OS that is suffering :-).
I don't know the correct way of solving this yet, but it's been
reported that issuing the ENABLE command after resumption wakes up the
pointing device.
Without PSM_HOOKAPM, the psm driver behaves in the same way as before.
Problem reported in the bsd-nomads mailing list in Japan.
Fixed bitrot (__dead went away; EOF is now wrong for the getopt failure
value).
Moved sleep command to the end of the main loop to avoid mismatch between
main loop and the report loop. There is an extra iteration that could be
used to calibrate the loop overhead, but was used to report wrong results.
Fixed usage message.
