libthr and 1:1 threading.
Terry Lambert
tlambert2 at mindspring.com
Wed Apr 2 15:32:44 PST 2003
Peter Wemm wrote:
> No. It gives the ability for a thread to block on a syscall without
> stalling the entire system. Just try using mysqld on a system using libc_r
> and heavy disk IO. You can't select() on a read() from disk. Thats the
> ultimate reason to do it. The SMP parallelism is a bonus.
Bug in FreeBSD's NBIO implementation. A read() that would result
in page-in needs to queue the request, but return EAGAIN to user
space to indicate the request cannot be satisfied. Making select()
come true for disk I/O after the fault is satisfied is a seperate
issue. Probably need to pass the fd all the way down.
-- Terry
More information about the freebsd-current
mailing list