Re: [PATCH/RESEND v2 0/2] Hard disk S3 resume time optimization

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, Jan 7, 2014 at 4:55 PM, Todd E Brandt
<todd.e.brandt@xxxxxxxxxxxxxxx> wrote:
>
> This patch reduces S3 resume time from 10+ seconds to less than a second
> on systems with SATA drives. It does this by making ata port and scsi disk
> resume non-blocking.
>
> This is another resend of the patch I send out in early December. I've
> addressed all the feedback I received from list members, so all I really
> need is a yay or nay from Tejun Huo and James Bottomley (since it touches
> both subsystems).
>
> The notes below include the performance results and patch description.
>
> [Computer One Test - 10.5X speedup on S3 resume]
> Platform: Ubuntu Raring Ringtail (13.04) kernel 3.11.0-rc7
> Cpu: Intel(R) Core(TM) i7-3960X CPU @ 3.30GHz
> Ahci: Intel C600/X79 series chipset 6-Port SATA AHCI (r5)
> Disk config (using all 6 ahci ports):
> 240 GB SSD, 3 TB HD, 500 GB HD, DVD-ROM (with cd inserted), 2 TB HD, 1 TB HD
> Resume time: [unpatched 11656ms] [patched 1110ms]
>
> [Computer Two Test - 12X speedup on S3 resume]
> Platform: Ubuntu Raring Ringtail (13.04) kernel 3.11.0-rc7
> Cpu: Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz
> Ahci: Intel 7 Series/C210 Series Chipset Family 6-port SATA [AHCI mode] (r4)
> Disk config (using 1 ahci port): 320 GB Hard Disk
> Resume time: [unpatched 5416 ms] [patched 448 ms]
>
> [Computer Three Test - 7.8X speedup on S3 resume]
> Platform: Ubuntu Raring Ringtail (13.04) kernel 3.11.0-rc7
> Cpu: Intel(R) Core(TM) i7-4770S CPU @ 3.10GHz
> Ahci: Intel Lynx Point 6-port SATA Controller 1 [AHCI mode] (r2)
> Disk config (using 2 ahci ports): DVD-ROM (empty), 500 GB Hard Disk
> Resume time: [unpatched 5385ms] [patched 688ms]
>
> The essential issue behind hard disks' lengthy resume time is the ata port
> driver blocking until the ATA port hardware is finished coming online. So
> the kernel isn't really doing anything during all those seconds that the
> disks are resuming, it's just blocking until the hardware says it's ready
> to accept commands. Applying this patch set allows SATA disks to resume
> asynchronously without holding up system resume, thus allowing the UI to
> come online much more quickly.
Won't this patch defeat staggered spinup at resume? If you have a jbod
with a smallish power supply, with a 12V rail designed for the steady
state and 1 or 2 devices spinning up at once, you may be in trouble
when all the disks will want to spinup in same second.

Gwendal.
> There may be a short period after resume
> where the disks are still spinning up in the background, but it will only
> momentarily affect applications using that disk.
>
> The patch set has two parts which apply to ata_port_resume and sd_resume
> respectively. Both are required to achieve any real performance benefit,
> but they will still function independantly without a performance hit.
>
> ata_port_resume patch (1/2):
> sd_resume patch (2/2):
>
> v2:
>  [in response to Oliver Neukum]
>  - Added scsi cmd error reporting through the scsi_sense_hdr
>  [in response to James Bottomley]
>  - unified the sd_resume code path by just making sd_resume async. Thus all
>    three resume callbacks: resume, restore, and runtime-resume will use it,
>    but there is a performance benefit for resume only.
>  [in response to Bartlomiej Zolnierkiewicz]
>  - unified the __ata_port_resume_common code path to include an async
>    parameter. This way there's no need to re-implement ata_port_request_pm.
>
> --
> 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




[Index of Archives]     [Linux Filesystems]     [Linux SCSI]     [Linux RAID]     [Git]     [Kernel Newbies]     [Linux Newbie]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Samba]     [Device Mapper]

  Powered by Linux