path into the kernel. Normally it's due to a syscall, but one can
also be created as the result of a clock interrupt (for example).
This now even more looks like exec_setregs().
While here, add an assert that we don't expect more than 8KB of
dirty registers on the kernel stack.
unconditionally restore ar.k7 (kernel memory stack) and ar.k6
(kernel register stack). I don't know what I was smoking then,
but if you unconditionally restore ar.k6, you also want to
compute its value unconditionally. By having the computation
predicated and dependent on whether we return to user mode, we
would end up writing junk (= invalid value for ar.bspstore) if
we would return to kernel mode. But the whole point of the
unconditional restoration was that there is a grey area where
we still need to have ar.k6 restored. If we restore with a junk
value, we would end up wedging the machine on the next interrupt.
So, unconditionally calculate the value we unconditionally write
to ar.k6.
o The previous braino was found while making the following change:
We used to clear the lower 9 bits of the value we write to ar.k6.
The meaning being that we know that the kernel register stack is
at least 512 byte aligned and simply clearing the lower 9 bits
allows us to return to a context of which we don't have dirty
registers on the kernel stack, even though the context that
entered the kernel does have dirty registers on the kernel stack.
By masking-off the lower bits, we correctly obtain the base of
the register stack without having to worry that we didn't actually
reached the base while unwinding it.
The change is to mask off the lower 13 bits, knowing that the
kernel register stack is always 8KB aligned. The advantage is that
we don't have to worry anymore if there's more than 512 bytes of
dirty registers on the kernel stack. A situation that frequently
occurs. In exec_setregs() in machdep.c:1.147 or older, we had to
deal with that situation by copying the active portion of the
register stack down in multiples of 512 bytes. Now that we mask off
the lower 13 bits we don't have to do that at all. Contemporary
IPF processors have a register file that can hold up to 96 stacked
registers (=784 bytes [incl. 2 NaT collections]). With no indication
that register files grow beyond a couple of hundred registers, we
should not have to worry about it anymore... and yes, 640KB is
enough for everybody :-)
This change helps setcontext(2) and cpu_set_upcall_kse() in that
they can return to completely different contexts without having to
mess with the kernel stack. Of course exec_setregs() doesn't need
to do that anymore as well.
queues lock such that it isn't held around the call to get_pv_entry(),
which calls uma_zalloc(). At the point of the call to get_pv_entry(), the
lock isn't necessary and holding it could lead to recursive acquisition,
which isn't allowed.
that the page's busy flag could be relied upon to synchronize access to the
pv list. I don't any longer. See, for example, the call to
pmap_insert_entry() from pmap_copy().)
(short) types for the port arg of inb() (rev.1.56). The warning started
working for u_short types with gcc-3.3. The pessimizations exposed
by this been fixed except for the cx and oltr drivers where the breakage
of the warning has been pushed to the drivers.
completenss. The pessimization is tiny compared with i/o port slowness
except on very old machines, but code that used signed short types for
i/o ports was unpessimized long ago, and the macro that detected it
recently started working for u_short types too. Use of bus space
should have made this moot long ago.
Not tested at runtime by: bde
completenss. The pessimization is tiny compared with i/o port slowness
except on very old machines, but code that used signed short types for
i/o ports was unpessimized long ago, and the macro that detected it
recently started working for u_short types too. Use of bus space
should have made this moot long ago.
Not tested at runtime by: bde
This change allows one to specify almost the complete traffic parameters
for IPoverATM channels through the routing table. Up to now we used
4 byte DL addresses (flag, vpi, vciH, vciL). This format is still allowed.
If the address is longer, however, the 5th byte is interpreted as the
traffic class (UBR, CBR, VBR or ABR) and the remaining bytes are the
parameters for this traffic class:
UBR: 0 byte or 3 byte PCR
CBR: 3 byte PCR
VBR: 3 byte PCR, 3 byte SCR, 3 byte MBS
ABR: 3 byte PCR, 3 byte MCR, 3 byte ICR, 3 byte TBE, 1 byte NRM,
1 byte TRM, 2 bytes ADTF, 1 byte RIF, 1 byte RDF and 1 byte CDF
A script to generate the corresponding 'route add' arguments will follow soon.
connection is to be established asynchronously, behave as in the
case of non-blocking mode:
- keep the SS_ISCONNECTING bit set thus indicating that
the connection establishment is in progress, which is the case
(clearing the bit in this case was just a bug);
- return EALREADY, instead of the confusing and unreasonable
EADDRINUSE, upon further connect(2) attempts on this socket
until the connection is established (this also brings our
connect(2) into accord with IEEE Std 1003.1.)
function prototypes. Use LIST_FOREACH instead of explicit loops.
The indentation of functions indendet by 4 space have been left alone.
2-space indented functions have been re-indented.
Eliminate a lot of checkes to make sure requests are not cross-device
which is unnecessary with the new layout. We know a sequential request
cannot possibly be cross-device because there is a reserved page between
the devices.
Remove a couple of comments which no longer are relevant.
i/o ports by calling the implementation-detail level below inb() and
outb() instead of inb() and outb(). Unpessimizing the types is too
hard since they are mainly used in microcode.
no longer existing "fixit" crunched binary).
- Simplify the CRUNCH_TARGETS variable's initialization.
- Simplify the release.5 logic a bit by accounting for the fact
that release/*_crunch.conf files were removed two years ago.
TCB. We know that the thread pointer points to &tcb->tcb_tp, so all
we have to do is subtract offsetof(struct tcb, tcb_tp) from the
thread pointer to get to the TCB. Any reasonably smart compiler will
translate accesses to fields in the TCB as negative offsets from TP.
In _tcb_set() make sure the fake TCB gets a pointer to the current
KCB, just like any other TCB. This fixes a NULL-pointer dereference
in _thr_ref_add() when it tried to get the current KSE.
