Messages in this thread | | | Subject | Re: [PATCH] 2.5.14 IDE 56 | Date | Thu, 9 May 2002 14:32:09 +0100 (BST) | From | Alan Cox <> |
| |
> You are right on the money! > There is about 35-40% throughput killjoy "copy-from-kernel-to-userspace". > It is easy to demo if you have a bus analizer and can do accounting on the > data io less the command block overhead. > > CR3's are your friend, not ...
You should be able to verify that by using large O_DIRECT I/O's. The block layer itself may well be part of the overhead. With the scsi layer, the block->scsi handling code is definitely a bottleneck to performance - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |