On Wednesday, February 27, 2013 12:58:11 am rihad wrote: > Now about this part taken from here > http://lists.freebsd.org/pipermail/freebsd-scsi/2011-March/004839.html > > By issuing a dummy read operation (thus forcing a flush of data > buffers), this issue is largely averted. > > Does this mean that battery-backed cache (BBU) is effectively rendered > useless, as all write operations are forced on to the disk platters on > every interrupt?
No, this is a very different level. This is forcing pending PCI DMA transactions on the PCI bus to flush by doing a read, not forcing I/O buffers to be flushed to disk. -- John Baldwin _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
