On Sat, Oct 11 2008, James Bottomley wrote: > On Fri, 2008-10-10 at 17:55 -0700, Arjan van de Ven wrote: > > On Fri, 10 Oct 2008 22:05:28 +0200 > > Jens Axboe <jens.axboe@xxxxxxxxxx> wrote: > > > > > > In this specific patch, it'll do no harm at least since I very much > > > doubt we'll see a false positive. And even if, the consequences wont > > > be dire. But it does want the version check, of course. > > > > > > > also, is "is an ssd" the right question or is "doesn't have seek > > latency" the right one? > > (difference is.. well EMC boxes with lots of ram etc) > > For libata, the is ssd is the right test. > > For things like the symmetrix we probably need to look at the caching > mode page and treat it like ssd if the cache is say > 1GB or whatever > heuristic is needed. Still wont quite work, you're still going to have occasional seek latencies no matter how large the cache is (unless it's == device size :-) So we need something a bit more involved, but not too complex. A fine line... -- Jens Axboe -- 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
