happens, the context of the interrupted thread is exported to
userland. Unlike most contexts, it will be an async context and
we cannot easily use our existing functions to set such a
context.
To avoid a lot of complexity that may possibly interfere with
the common case, we simply let the kernel deal with it. However,
we don't use the EPC based syscall path to invoke setcontext(2).
No, we use the break-based syscall path. That way the trapframe
will be compatible with the context we're trying to restore and
we save the kernel a lot of trouble. The kind of trouble we did
not want to go though ourselves...
However, we also need to set the threads mailbox and there's no
syscall to help us out. To avoid creating a new syscall, we use
the context itself to pass the information to the kernel so that
the kernel can update the mailbox. This involves setting a flag
(_MC_FLAGS_KSE_SET_MBOX) and setting ifa (the address) and isr
(the value).
when we create contexts. The meaning of the flags are documented in
<machine/ucontext.h>. I only list them here to help browsing the
commit logs:
_MC_FLAGS_ASYNC_CONTEXT
_MC_FLAGS_HIGHFP_VALID
_MC_FLAGS_KSE_SET_MBOX
_MC_FLAGS_RETURN_VALID
_MC_FLAGS_SCRATCH_VALID
Yes, _MC_FLAGS_KSE_SET_MBOX is a hack and I'm proud of it :-)
wctob() in terms of wcrtomb() instead of sputrune(). There should be
no functional differences, but there may be a small performance hit
because we make an extra function call.
The aim here is to have as few functions as possible calling
s{get,put}rune() to make it easier to remove them in the future.
o For trap-based upcalls the argument (the kse_mailbox) to
the UTS must be written onto the kernel stack, not the
user stack. While here, deal with the fact that we may
be at a NaT collection point.
- Rename linkstatus to linkstate which is more correct.
- Sort any leases each time we loose and regain link. With the first
version we spammed the dhclient.leases file.
- When there was no link on a interface, polling has been done twice.
This has been fixed with a bigger sleep interval.
- interface_active() now returns only a assumed state of the link.
If we are using media settings, we cannot be sure that the link
actually works. That means we assume that the link is working and
continue to send requests as usual on the interface and loop over
all possible media options. Polling is still done. If your interface
gets suddenly link, dhclient will send a dhcp discover request.
After all media settings have been tried a few times, dhclient will
sleep. If one does change networks very often, it can help to set the
"retry timeout" to a low value like 100 seconds. The default is over
six minutes.
Tested by: Larry Rosenman <ler@lerctr.org>, imp
- Fix a bug in rl_dma_map_desc(): set the 'end of ring' bit in the
right descriptor (DESC_CNT - 1, not DESC_CNT). The 8139C+ is limited
to 64 descriptors and automatically wraps at 64 descriptors even
if the EOR bit isn't set, but the 8169 NIC can have up to 1024
descriptors per ring, so we must set the wrap point in the right
place.
- RealTek moved the RL_TIMERINT register from offset 0x54 to 0x58 in
the 8169 -- account for this.
- Added rl_gmii_readreg() and rl_gmii_writereg() routines.
- Fix rl_probe() to deal with the case where the base type is
not RL_8139.
The next step is to add jumbo buffer support.
Tested with the Xterasys XN-152 NIC (hard to beat $29 for a gigE NIC).
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.
