PATCH: improved processor config for G3s
Benjamin Herrenschmidt
bh40 at calva.net
Tue Sep 5 21:50:25 EST 2000
>
>The absence of broadcast might definitely harm, but first the support for
>store gathering in the MPC106 (Grackle) is quite poor:
>
>"For a stream of single-beat writes, the data for the first transaction is
>latched in the first buffer and the MPC106 initiates the transaction on
>the PCI bus. The second single-beat write is then stored in the second
>buffer. For subsequent single-beat writes, store gathering is possible if
>the incoming write is to sequential bytes in the same half cache line as
>the previously latched data. Store gathering is only used for writes to
>PCI memory space, not for writes to PCI I/O space. The store gathering
>continues until the buffer is scheduled to be flushed or until the
>processor issues a synchronizing transaction.
Well, that would help unaccelerated frame buffers (but are there any on
Grackle-based machines ?)
** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/
More information about the Linuxppc-dev
mailing list