Re: [git patches] libata updates for 3.3

[Linus Torvalds]

On Mon, Jan 16, 2012 at 11:29 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> and I do think that resume used to be faster in v3.2 than it is even
> with your patch. But maybe that's some rose-colored glasses.
>
> I'll recompile an old kernel to check.

Confirmed.

Plain v3.2 really *is* faster than current git, even current git with
your patch.

In v3.2 I get this:

 [   92.035600] ata_piix 0000:00:1f.2: PCI INT B -> GSI 19 (level,
low) -> IRQ 19
 [   92.035610] ata_piix 0000:00:1f.2: setting latency timer to 64
 [   92.036213] sd 0:0:0:0: [sda] Starting disk
 [   93.060471] ata2.00: failed to resume link (SControl 0)
 [   93.379963] ata1.01: failed to resume link (SControl 0)
 [   93.535802] ata1.00: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
 [   93.535815] ata1.01: SATA link down (SStatus 0 SControl 0)
 [   93.543968] ata1.00: ACPI cmd ef/03:46:00:00:00:a0 (SET FEATURES)
filtered out
 [   93.544747] ata1.00: configured for UDMA/100
 [   93.916453] PM: resume of devices complete after 1883.974 msecs
 [   93.916677] PM: Finishing wakeup.
 [   94.086800] ata2.01: failed to resume link (SControl 0)
 [   94.098408] ata2.00: SATA link down (SStatus 4 SControl 0)
 [   94.098429] ata2.01: SATA link down (SStatus 0 SControl 0)

while current git (with your patch) gives me

 [  108.115373] ata_piix 0000:00:1f.2: setting latency timer to 64
 [  109.142010] ata2.00: failed to resume link (SControl 0)
 [  109.462004] ata1.01: failed to resume link (SControl 0)
 [  109.618065] ata1.00: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
 [  109.618078] ata1.01: SATA link down (SStatus 0 SControl 0)
 [  109.626242] ata1.00: ACPI cmd ef/03:46:00:00:00:a0 (SET FEATURES)
filtered out
 [  109.627060] ata1.00: configured for UDMA/100
 [  109.627240] sd 0:0:0:0: [sda] Starting disk
 [  110.170015] ata2.01: failed to resume link (SControl 0)
 [  110.181480] ata2.00: SATA link down (SStatus 4 SControl 0)
 [  110.181496] ata2.01: SATA link down (SStatus 0 SControl 0)
 [  110.182124] PM: resume of devices complete after 2066.945 msecs
 [  110.224533] PM: Finishing wakeup.

so old kernels used to be a tiny bit faster despite not doing that
async thing (still slower than I'd like: I'd think that we should be
able to resume devices in less than a second, but I don't know where
all the time goes)

             Linus
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