On Thu, Dec 04, 2014 at 03:11:02PM -0800, Andrew Morton wrote: > I can see all that, but it's handwaving. Yes, preadv2() will perform > better in some circumstances than fincore+pread. But how much better? > Enough to justify this approach, or not? > > Alas, the only way to really settle that is to implement fincore() and > to subject it to a decent amount of realistic quantitative testing. > > Ho hum. > > Could you please hunt down some libuv developers, see if we can solicit > some quality input from them? As I said, we really don't want to merge > this then find that people don't use it for some reason, or that it > needs changes. All I can say from a Samba perspective is that none of the ARM based Storage boxes I have seen so far do AIO because of the base footprint for every read. For sequential reads kernel-level readahead could kick in properly and we should be able to give them the best of both worlds: No context switches in the default case but also good parallel behaviour for other workloads. The most important benchmark for those guys is to read a DVD image, whether it makes sense or not. Volker -- SerNet GmbH, Bahnhofsallee 1b, 37081 Göttingen phone: +49-551-370000-0, fax: +49-551-370000-9 AG Göttingen, HRB 2816, GF: Dr. Johannes Loxen http://www.sernet.de, mailto:kontakt@xxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
