"I sometimes find myself on either slow or data-capped network links where downloading images isn't ideal. Attached is a simple patch to mothra that changes the 'k' command to not only remove already-downloaded images from a page, but also toggle a state such that mothra won't attempt to download images on future visited sites until 'k' is toggled again. This also adds a '-k' flag to mothra which enables the flag at startup." --Jeremy O'Brien<neutral@fastmail.com> on 9fans
the target has to be encoded as a domain name (the individual
name components as separate labels followed by . (empty) label),
not as a literal string.
to disable compression, pass nil dictionary to pname().
- fix overwriting channel 10 with channel 9
- fix using channel volume instead of last volume when setting note
(fixes d_doom and others)
- remove useless state
we did not apply the special case to store 0xFFFF (-0)
in the checksum field when the checksum calculation
returned zero. we survived this for v4 as RFC768 states:
> If the computed checksum is zero, it is transmitted as
> all ones (the equivalent in one's complement arithmetic).
>
> An all zero transmitted checksum value means that the
> transmitter generated no checksum (for debuging or for
> higher level protocols that don't care).
for ipv6 however, the checksum is not optional and receivers
would drop packets with a zero checksum.
during dhcp, ipconfig assigns the null address :: which makes
ipforme() return Runi for any destination, which can trigger
arp resolution when we attempt to reply. so have v4local()
skip the null address and have sendarp() check the return
status of v4local(), avoing the spurious arp requests.
closeconv() calls ipifcremmulti() like:
while((mp = cv->multi) != nil)
ipifcremmulti(cv, mp->ma, mp->ia);
so we have to defer freeing the entry after doing:
if((lifc = iplocalonifc(ifc, ia)) != nil)
remselfcache(f, ifc, lifc, ma);
which accesses the otherwise free'd ia and ma arguments.
on HZ 100 systems like pc and pc64, the minium sleep time
was 10ms, which is quite high. the cap isnt really needed
as arch specific timerset() enforces its own limit, but on
a higher resolution.
background:
from Charles Forsyth:
I haven't really got an opinion on it. The 10ms interval was first used on
machines that were much slower.
I thought someone did set HZ to a bigger value, partly to support better
in-kernel timing. I haven't done it because I never had a need for it.
If I were doing (say) protocol implementation in user mode, I'd certainly
reconsider. Sleep itself forces at best ms granularity,
and for some applications that's too big.
initial mail from qwx raising the issue:
> Hello,
>
> I found out recently that sleep(2)'s resolution on 386 and 9front's amd64
> kernel is 10 ms rather than 1 ms. The reason is that on those kernels,
> HZ is set to 100 rather than say 1000. In syssleep, we get 1 tich every
> 10 ms.
>
> What is unclear is why.
>
> To paraphrase cinap_lenrek's answer to my question:
>
> In syssleep:
> if(ms < TK2MS(1))
> ms = TK2MS(1);
> tsleep(&up->sleep, return0, 0, ms);
>
> "TK2MS(1)" can be replaced with just "1", and the arch specific
> timerset() routine would do its own capping of the period if it's too
> small for the timer resolution, and make better decisions based on what
> the minimum timer period should be given the latency overhead of the
> given arch's interrupt handling and performance characteristics.
>
> Alternatively, HZ could be raised to 500 or 1000.
>
> It seems it's just trying to prevent excessive context switches and
> interrupts, but it seems somewhat arbitrary. A ton of syscalls can be
> done in 1 ms, and it's the lowest we can go without changing the unit.
>
>
> What do you think?
>
> Thanks in advance,
>
> qwx
