read/write/accept, then the expectation is that the blocked thread will
exit and the close complete.
Since only one fd is affected, but many fd can refer to the same file,
the close code can only request the fs code unblock with ERESTART.
Fixed for pipes and sockets, ERESTART will only be generated after such
a close - so there should be no change for other programs.
Also rename fo_abort() to fo_restart() (this used to be fo_drain()).
Fixes PR/26567
Only sleep once within each pipe_read/pipe_write call.
If there is no data/space available after we wakeup return ERESTART so
then the 'fd' number is validated again.
A simple broadcast of the cvs is then enough to evict the correct threads
when close() is called from an active thread.
Only one fd needs clobbering, not all fds that reference the pipe.
This may be what ad@ realised when he tried to add the same code to
sockets. Unfixes part of PR/26567.
do drain' in many places, whereas fo_drain() was called in order to force
blocking read()/write() etc calls to return to userspace so that a close()
call from a different thread can complete.
In the sockets code comment out the broken code in the inner function,
it was being called from compat code.
activity of other threads will perform the TLB flush for the processes using
emap as a side effect. To track that, global and per-CPU generation numbers
are used. This idea was suggested by Andrew Doran; various improvements to
it by me. Notes:
- For now, zero-copy on pipe is not yet enabled.
- TCP socket code would likely need more work.
- Additional UVM loaning improvements are needed.
Proposed on <tech-kern>, silence there.
Quickly reviewed by <ad>.
than one active reference to a file descriptor. It should dislodge threads
sleeping while holding a reference to the descriptor. Implemented only for
sockets but should be extended to pipes, fifos, etc.
Fixes the case of a multithreaded process doing something like the
following, which would have hung until the process got a signal.
thr0 accept(fd, ...)
thr1 close(fd)
- Cache kva.
- Convert to use mutex_obj_alloc().
- Make better use of pool_cache.
Also:
Disable direct transfers for the moment. I believe there may be a bug that
can cause transfers to stall when switching between direct/buffered access.
I think this has most recently been run into on 'denver' but I have seen it
as far back as 3.1.
(As an aside, direct is a not a clear win on modern systems with large cache
and high TLB invalidation overhead. Particularly so on MP systems, although
micro benchmarks may report otherwise because they typically do not tax the
system. Anyone want to write a decent benchmark?)
- Add a lot of missing selinit() and seldestroy() calls.
- Merge selwakeup() and selnotify() calls into a single selnotify().
- Add an additional 'events' argument to selnotify() call. It will
indicate which event (POLL_IN, POLL_OUT, etc) happen. If unknown,
zero may be used.
Note: please pass appropriate value of 'events' where possible.
Proposed on: <tech-kern>
this fixes a deadlock between pipe_direct_write and pipeclose.
XXX this code should be simplified.
it's mostly pointless to have two struct pipes linked together,
esp. when we don't support bi-directional pipes.
int foo(struct lwp *l, void *v, register_t *retval)
to:
int foo(struct lwp *l, const struct foo_args *uap, register_t *retval)
Fixup compat code to not write into 'uap' and (in some cases) to actually
pass a correctly formatted 'uap' structure with the right name to the
next routine.
A few 'compat' routines that just call standard ones have been deleted.
All the 'compat' code compiles (along with the kernels required to test
build it).
98% done by automated scripts.
uebayasi