On Wed, 5 Nov 2003, Robert Watson wrote: > On Wed, 5 Nov 2003, Igor Sysoev wrote: > > > As to worker kthreads I think it's better to queue aio operation as it > > was made in src/sys/kern/vfs_aio.c:aio_qphysio(). > > One of the things that worries me about the proposal to use kernel worker > threads to perform the I/O is that this can place a fairly low upper bound > on effective parallelism, unless the kernel threads themselves can issue > the I/O's asynchronously. In the network stack itself, we are event and > queue driven without blocking--if we can maintain the apparent semantics > to the application, it would be very nice to be able to handle that at the > socket layer itself. I.e., not waste a thread + stack per "in-progress" > operation, and instead have a worker or two that simply propel operations > up and down the stack (similar to geom_up and geom_down).
As far as I understand src/sys/kern/vfs_aio.c:aio_qphysio() (that handles AIO on raw disks) does not use kthreads and simply queues operations. Igor Sysoev http://sysoev.ru/en/ _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
