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. -- 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
