*after* writing, the directory tree gets alphabetically sorted for
path table. this causes data to not be in the same order as it was
written causing seeks when taring up the filesystem.
so instead write the files in alphabetical order as well to better
match the directory sorting.
data on the disk is layed out sequentially and directory information
is at the end of the disk. we want to keep data and metadata separated
so that reading large sequential files will not evict the directory
information from the cache causing long seeks.
for that, we tag the clusters (an 8th for metadata, and the rest
for data) and getbuf() will only evict clusters of the same tag.
doing tests taring up 9front.iso shows the following:
lowering the cluster size back to 128k avoids over half the
reads. 837888 sectors read for 512k vs. 347712 sectors with
128k cluster size.
foo.c includes bar/bar.h, which includes "baz.h"; it wants bar/baz.h
meanwhile, it also includes meh/quux.h, which includes "baz.h"; it wants meh/baz.h
Wnode gets two new counters: txcount and txerror
and actrate pointer that will be between minrate
and maxrate.
driver should use actrate instead of maxrate for
transmission when it can provide error feedback.
when a driver detects a transmission failed, it calls
wifitxfail() with the original packet. wifitxfail() then
reduces wn->actrate.
every 256th packet, we optimistically increase wn->actrate
before transmitting.
- reject files smaller or equal to two bytes, they are bogus
- fix out of bounds access in shargs() when n <= 2
- only copy the bytes read into line buffer
- use nil for pointers instead of 0
imagereclaim(), pagereclaim():
- move imagereclaim() and pagereclaim() declarations to portfns.h
- consistently use ulong type for page counts
- name number of pages to free "pages" instead of "min"
- check for pages == 0 on entry
freepages():
- move pagechaindone() call to wakeup newpage() consumers inside
palloc critical section.
putimage():
- use long type for refcount
- reduce delay for channel hop to 200ms
- use 1000ms timeout for auth response (dont hop channels while we wait)
- bunny hop sequence is mathematically prooven
