On Fri, Jan 16, 2015 at 3:17 PM, Jens Axboe <axboe@xxxxxx> wrote: > On 01/16/2015 04:13 PM, Dan Williams wrote: >> Jens notes, "libata tag allocator sucks. Like seriously sucks, it's >> almost a worst case implementation." Previously I thought SATA mmio >> latency dominated performance profiles, but as Tejun notes: >> >> "Hmmm... one problem with the existing tag allocator in ata is that >> it's not very efficient which actually shows up in profile when libata >> is used with a very zippy SSD. Given that ata needs a different >> allocation policies anyway maybe the right thing to do is making the >> existing allocator suck less." >> >> So replace it with a naive enhancement that also supports the existing >> quirks. Hopefully, soon to be replaced by Shaohua's patches [1], but >> those do not yet support the quirk needed by sil24 (ATA_FLAG_LOWTAG) >> [2]. > > That's trivial to do, it's just always having '0' in the cache and > that's where the search would start. > Cool. -- 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
