long. This is used to check for interrupts being disabled at the time
of a lock() call, if enabled in config.h. The number of times this
happens is then counted in the kinfo structure. These events (recursive
lockings) lead to nasty race conditions.
The TTY driver now only notifies the IS server about function key event,
but does not tell which keys are pressed. The IS servers queries the TTY
driver to find out about this.
variable. Parsing worked, but future requests for the variable (such as
by the sysenv command) returned truncated data. This caused the system
(e.g. setup script) to think the amount of memory was tiny, and caused
the enabling of swapspace, while it is unnecessary.
syncing, for instance) if blocks are unwritable. This could happen if:
. write goes beyond device boundary to a block device
. write is done for a complete block or more; thus the
block is not retrieved first (at which point it would be noticed
it doesn't exist), but the buffer is simply allocated
. at write time, the device i/o doesn't succeed, but rw_scattered
doesn't understand this and loops forever trying to get the block
written.
Currently, if no blocks can be written, the loop aborts, leaving all
buffers intact but potentially dirty. When invalidate() is called on the
device, the buffers will disappear (even if dirty). Same story for if
the buffer is removed due to rmed from lru chain. There's not much we
can do about this, however - we can't keep these blocks around, forever
occupying a buffer in the buffer cache.
The second part of the solution is not to let unwritable buffers be
created in the first place. How to do this, however, without doing a
wasteful read first?
It looks like this code was in 2.0.4 too.
Added interface to select() for pipes (also named pipes), and select()
stubs for regular files.
Added timer library in FS that select() is the first customer of.
This is unfinished, but committed anyway to get a new release out to
Al and testers.
caused interrupts to be reenabled (due to unlock), which caused a race. The
problems were especially visible on slower machines.
* Relocated free memory parsing to process manager. This saved quite some
code at the kernel level. Text size was reduced by about 650 bytes.
* Removed locks for updating the realtime in the clock's main loop and the
get_uptime function. Interrupts are no longer reentrant, so realtime is
immediately updated.
Reduced kernel size by 512KB by moving private buffer into cstart() function.
Replaced assertions with erroneous return values. Removed assertions relating
to isuserp(rp), since all processes should become user processes; system
processes are now treated similar to other processes.
