This is the final draft of the non-blocking hard disk resume patch. I've included some performance results to demonstrate the real benefits of this patch. Please note that this patch provides a MASSIVE performance improvement in hard disk resume. It's too valuable to ignore, so I really need the help of the maintainers to get this implemented. Even if this patch is deemed the wrong approach I hope you won't abandon the idea altogether. There is so much potential in this kind of optimization and I'm highly motivated to make this work. To demonstrate the substantial performance improvement I've run the AnalyzeSuspend tool on three different platforms patched with the new behavior. Each is running Ubuntu Raring with a kernel built from the upstream kernel source. The complete analysis and graphical outputs of the tool are available online at 01.org: https://01.org/suspendresume/blogs/tebrandt/2013/hard-disk-resume-optimization-simpler-approach Here's a synopsis of the results. ------------------------------------------------------- [Computer One] PLATFORM: Ubuntu Raring Ringtail (13.04) KERNEL: 3.11.0-rc7 CPU: Intel(R) Core(TM) i7-3960X CPU @ 3.30GHz SATA: Intel C600/X79 series chipset 6-Port SATA AHCI (r5) DISK CONFIG: ATA1: 240 GB SSD ATA2: 3 TB Hard Disk ATA3: 500 GB Hard Disk ATA4: DVD-ROM (with cd inserted) ATA5: 2 TB Hard Disk ATA6: 1 TB Hard Disk RESUME TIME WITHOUT PATCH: 11656 ms RESUME TIME WITH PATCH: 1110 ms IMPROVEMENT: 10.5X speedup ------------------------------------------------------- [Computer Two] PLATFORM: Ubuntu Raring Ringtail (13.04) KERNEL: 3.11.0-rc7 CPU: Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz SATA: Intel 7 Series/C210 Series Chipset Family 6-port SATA [AHCI mode] (r4) DISK CONFIG: ATA1: 320 GB Hard Disk ATA2 - ATA6: Empty slots RESUME TIME WITHOUT PATCH: 5416 ms RESUME TIME WITH PATCH: 448 ms IMPROVEMENT: 12X speedup ------------------------------------------------------- [Computer Three] PLATFORM: Ubuntu Raring Ringtail (13.04) KERNEL: 3.11.0-rc7 CPU: Intel(R) Core(TM) i7-4770S CPU @ 3.10GHz SATA: Intel Lynx Point 6-port SATA Controller 1 [AHCI mode] (r2) DISK CONFIG: ATA1,3,4,6: Empty Slots ATA2: DVD-ROM (empty) ATA5: 500 GB Hard Disk RESUME TIME WITHOUT PATCH: 5385 ms RESUME TIME WITH PATCH: 688 ms IMPROVEMENT: 7.8X speedup ------------------------------------------------------- Signed-off-by: Todd Brandt <todd.e.brandt@xxxxxxxxx> Signed-off-by: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx> drivers/ata/libata-core.c | 36 +++++++++++++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index c24354d..6cf0c15 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -5415,6 +5415,40 @@ static int ata_port_resume(struct device *dev) return rc; } +static int ata_port_resume_async(struct device *dev) +{ + struct ata_port *ap = to_ata_port(dev); + struct ata_link *link; + unsigned long flags; + int ret = 0; + + if (ap->pflags & ATA_PFLAG_PM_PENDING) { + WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING); + ret = -EAGAIN; + goto out; + } + + spin_lock_irqsave(ap->lock, flags); + + ap->pm_mesg = PMSG_RESUME; + ap->pm_result = NULL; + ap->pflags |= ATA_PFLAG_PM_PENDING; + ata_for_each_link(link, ap, HOST_FIRST) { + link->eh_info.action |= ATA_EH_RESET; + link->eh_info.flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET; + } + + ata_port_schedule_eh(ap); + + spin_unlock_irqrestore(ap->lock, flags); + + out: + pm_runtime_disable(dev); + pm_runtime_set_active(dev); + pm_runtime_enable(dev); + return ret; +} + /* * For ODDs, the upper layer will poll for media change every few seconds, * which will make it enter and leave suspend state every few seconds. And @@ -5451,7 +5485,7 @@ static int ata_port_runtime_resume(struct device *dev) static const struct dev_pm_ops ata_port_pm_ops = { .suspend = ata_port_suspend, - .resume = ata_port_resume, + .resume = ata_port_resume_async, .freeze = ata_port_do_freeze, .thaw = ata_port_resume, .poweroff = ata_port_poweroff, -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
