> -----Original Message----- > From: linux-ide-owner@xxxxxxxxxxxxxxx [mailto:linux-ide- > owner@xxxxxxxxxxxxxxx] On Behalf Of Jeff Garzik > Sent: Saturday, February 11, 2012 2:26 AM > To: Liu Qiang-B32616 > Cc: linux-ide@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linuxppc- > dev@xxxxxxxxxxxxxxxx > Subject: Re: [PATCH V2] fsl-sata: I/O load balancing > > On 01/19/2012 09:19 PM, qiang.liu@xxxxxxxxxxxxx wrote: > > From: Qiang Liu<qiang.liu@xxxxxxxxxxxxx> > > > > Reduce interrupt signals through reset Interrupt Coalescing Control Reg. > > Provide dynamic method to adjust interrupt signals and timer ticks by > sysfs. > > It is a tradeoff for different applications. > > > > Signed-off-by: Qiang Liu<qiang.liu@xxxxxxxxxxxxx> > > --- > > > > change for V2 > > support dynamic config interrupt coalescing register by /sysfs > > test random small file with iometer > > Description: > > 1. fsl-sata interrupt will be raised 130 thousand times when write > 8G file > > (dd if=/dev/zero of=/dev/sda2 bs=128K count=65536); > > 2. most of interrupts raised because of only 1-4 commands completed; > > 3. only 30 thousand times will be raised after set max interrupt > threshold, > > more interrupts are coalesced as the description of ICC; > > > > Test methods and results: > > 1. test sequential large file performance, > > [root@p2020ds root]# echo 31 524287> \ > > /sys/devices/soc.0/ffe18000.sata/intr_coalescing > > [root@p2020ds root]# dd if=/dev/zero of=/dev/sda2 bs=128K > count=65536& > > [root@p2020ds root]# top > > > > CPU % | dd | flush-8:0 | softirq > > --------------------------------------- > > before | 20-22 | 17-19 | 7 > > --------------------------------------- > > after | 18-21 | 15-16 | 5 > > --------------------------------------- > > 2. test random small file with iometer, > > iometer paramters: > > 4 I/Os burst length, 1MB transfer request size, 100% write, 2MB > file size > > as default configuration of interrupt coalescing register, 1 > interrupts and > > no timeout config, total write performance is 119MB per second, > > after config with the maximum value, write performance is 110MB per > second. > > > > After compare the test results, a configuable interrupt coalescing > should be > > better when cope with flexible context. > > > > drivers/ata/sata_fsl.c | 111 > ++++++++++++++++++++++++++++++++++++++++++++++-- > > 1 files changed, 107 insertions(+), 4 deletions(-) > > Doesn't seem to apply to upstream, or another less recent -rc... Thanks, I will resend it latterly. > > Jeff > > > > -- > 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 -- 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
