>>>>> "Andrew" == Andrew Morton <[EMAIL PROTECTED]> writes:
Andrew> On Mon, 18 Jun 2007 14:14:30 -0700 Andrew> Tim Chen <[EMAIL PROTECTED]> wrote: >> IOZone write drops by about 60% when test file size is 50 percent of >> memory. Rand-write drops by 90%. Andrew> heh. Andrew> (Or is that an inappropriate reaction?) >> Is there a good reason for turning down the default dirty ratio? Andrew> It seems too large. Memory sizes are going up faster than Andrew> disk throughput and it seems wrong to keep vast amounts of Andrew> dirty data floating about in memory like this. It can cause Andrew> long stalls while the system writes back huge amounts of data Andrew> and is generally ill-behaved. Shouldn't the vm_dirty_ratio be based on the speed of the device, and not the size of memory? So slower devices can't keep as much in memory as fast devices? That would seem to be a better metric. And of course those with hundreds of disks will then complain we're taking too much memory as well, even though they can handle it. So per-device vm_dirty_ratio, capped with a vm_dirty_total_ratio seems to be what we want, right? John - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
