On Fri, Jan 16, 2015 at 03:13:08PM -0800, 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]. > > [1]: http://marc.info/?l=linux-ide&m=142137195324687&w=2 > [2]: https://bugzilla.kernel.org/show_bug.cgi?id=87101 > > Cc: Jens Axboe <axboe@xxxxxx> > Cc: Tejun Heo <tj@xxxxxxxxxx> > Cc: Shaohua Li <shli@xxxxxx> > Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> > Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> Hmmm... if libata using blk-tag isn't ugly, I think that prolly is the better way to proceed. Let's see how that develops. Thanks. -- tejun -- 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
