On Fri, Aug 14, 2009 at 5:45 PM, Matthew Wilcox<matthew@xxxxxx> wrote: > On Fri, Aug 14, 2009 at 05:21:32PM -0600, Chris Worley wrote: >> Sooner is better than waiting to coalesce. The longer an LBA is >> inactive, the better for any management scheme. If you wait until >> it's reused, you might as well forgo the advantages of TRIM/UNMAP. If >> a the controller wants to coalesce, let it coalesce. > > I'm sorry, you're wrong. There is a tradeoff point, and it's different > for each drive model. Sending down a steady stream of tiny TRIMs is > going to give terrible performance. Sounds like you might be using junk for a device? For junk, a little coalescing may be warranted... like in the I/O schedular, but no more than 100usecs wait before posting, or then you effect high performing devices too. Chris > > -- > Matthew Wilcox Intel Open Source Technology Centre > "Bill, look, we understand that you're interested in selling us this > operating system, but compare it to ours. We can't possibly take such > a retrograde step." > -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
