On 04/23/2014 01:11 AM, Dan Williams wrote: > On Mon, Apr 21, 2014 at 12:29 AM, Jet Chen <[email protected]> wrote: >> HI Dan, >> >> we noticed the below changes on >> >> git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata for-next >> commit 8a4aeec8d2d6a3edeffbdfae451cdf05cbf0fefd ("libata/ahci: accommodate >> tag ordered controllers") > > Hi, was this on simulated hardware or a real AHCI controller and disk? >
Testing was on a physical machine with a real AHCI controller. root@bay ~# lspci | grep AHCI 00:1f.2 SATA controller: Intel Corporation 82801IR/IO/IH (ICH9R/DO/DH) 6 port SATA Controller [AHCI mode] (rev 02) > It does appear this test noticed increased throughput: > > 203893 ~ 0% +3.7% 211474 ~ 0% TOTAL iostat.sda.wkB/s > > I wonder if ap->last_tag can be moved to a hotter cacheline, but if > throughput goes up I can imagine it throws off the cpu statistics > quite a bit. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
