[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] Re: [PATCH] stubdom: optimize block io completion polling
Samuel Thibault, le Wed 13 Feb 2008 13:59:59 +0000, a écrit : > stubdom: optimize block io completion polling > by not polling all the time but just when some requests have completed. Oops, sorry, although it never happened during my tests, I'm pretty sure there is a race, please use this patch instead: stubdom: optimize block io completion polling by not polling all the time but just when some requests have completed. Signed-off-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxxx> diff -r e85399173769 extras/mini-os/blkfront.c --- a/extras/mini-os/blkfront.c Tue Feb 12 16:59:08 2008 +0000 +++ b/extras/mini-os/blkfront.c Wed Feb 13 15:55:47 2008 +0000 @@ -327,6 +327,11 @@ struct blkif_response *rsp; moretodo: +#ifdef HAVE_LIBC + files[dev->fd].read = 0; + mb(); /* Make sure to let the handler set read to 1 before we start looking at the ring */ +#endif + rp = dev->ring.sring->rsp_prod; rmb(); /* Ensure we see queued responses up to 'rp'. */ cons = dev->ring.rsp_cons; --- a/tools/ioemu/block-vbd.c Tue Feb 12 16:59:08 2008 +0000 +++ b/tools/ioemu/block-vbd.c Wed Feb 13 15:55:47 2008 +0000 @@ -67,6 +67,12 @@ return 100; } +static void vbd_io_completed(void *opaque) +{ + BDRVVbdState *s = opaque; + blkfront_aio_poll(s->dev); +} + static int vbd_open(BlockDriverState *bs, const char *filename, int flags) { BDRVVbdState *s = bs->opaque; @@ -85,6 +91,7 @@ } s->fd = blkfront_open(s->dev); + qemu_set_fd_handler(s->fd, vbd_io_completed, NULL, s); QEMU_LIST_INSERT_HEAD(&vbds, s, list); @@ -102,9 +109,6 @@ void qemu_aio_poll(void) { - BDRVVbdState *s; - for (s = vbds.lh_first; s; s = s->list.le_next) - blkfront_aio_poll(s->dev); } /* Wait for all IO requests to complete. */ _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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