Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [Suspend-devel] Resume performance | Date | Tue, 9 Sep 2008 16:13:44 +0200 |
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On Sunday, 7 of September 2008, Anders Aagaard wrote: > Rafael J. Wysocki wrote: > > On Friday, 5 of September 2008, Anders Aagaard wrote: > >> Rafael J. Wysocki wrote: > >>> On Friday, 5 of September 2008, Anders Aagaard wrote: > >>>> Hi > >>> Hi, > >>> > >>> This is a kernel problem, so let's CC the LKML. > >>> > >>>> I have a intel P35 board with a quad core cpu in it, it's currently > >>>> running as a server for a small network, and I'd like to be able to shut > >>>> it down when idle, and use wake on lan to wake it up when it's needed. > >>>> Now I got that part working quite well, but for some reason I have a > >>>> long delay in resume. > >>>> > >>>> I seem to remember being able to resume this computer in 2-3 seconds > >>>> when I was testing it, now it needs 35 seconds to resume. It seems > >>>> regardless of resume options used, and it always resumes to a working > >>>> state without problems. > >>> What kernel are you using at the moment and which one was used for the > >>> testing? > >> I'm using gentoo's 2.6.25-r7, I've also tried vanilla sources. > > > > Would it be possible to test 2.6.27-rc5-gi7 from kernel.org? > > Tested, makes no difference. > > > > >>>> I've tried quite a lot of things, booting with noapic/nosmp, booting a > >>>> kernel without usb/network drivers, disabling ahci (using ata_piix > >>>> driver instead of ahci), and there's always that one long delay. And > >>>> I'm not quite sure how the kernel printk timing information works, so > >>>> I'm not sure whats causing that delay. > >>>> > >>>> Output from dmesg when booting with nosmp (to get accurate timing data): > >>>> scripts/show_delta -b "Force enabled HPET at resume" > >>>> [349.821150 < 7.039261 >] ata3.00: configured for UDMA/133 > >>>> [349.821160 < 7.039271 >] sd 2:0:0:0: [sdc] 976773168 512-byte hardware > >>>> sectors (500108 MB) > >>>> [349.821165 < 7.039276 >] sd 2:0:0:0: [sdc] Write Protect is off > >>>> [349.821166 < 7.039277 >] sd 2:0:0:0: [sdc] Mode Sense: 00 3a 00 00 > >>>> [349.821173 < 7.039284 >] sd 2:0:0:0: [sdc] Write cache: enabled, read > >>>> cache: enabled, doesn't support DPO or FUA > >>>> [349.972801 < 7.190912 >] ata1: SATA link up 3.0 Gbps (SStatus 123 > >>>> SControl 300) > >>>> [349.979060 < 7.197171 >] ata1.00: configured for UDMA/133 > >>>> [349.979070 < 7.197181 >] sd 0:0:0:0: [sda] 976771055 512-byte hardware > >>>> sectors (500107 MB) > >>>> [349.979075 < 7.197186 >] sd 0:0:0:0: [sda] Write Protect is off > >>>> [349.979076 < 7.197187 >] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00 > >>>> [349.979083 < 7.197194 >] sd 0:0:0:0: [sda] Write cache: enabled, read > >>>> cache: enabled, doesn't support DPO or FUA > >>> It looks like this happens here. Can you try to unload the network driver > >>> before suspend, please? > >> I tried to build a kernel without it, and it still takes the exact same > >> amount to boot, I've also tried unloading usb drivers and it takes the > >> exact same amount of time. > > > > Can you try to boot with init=/bin/bash and suspend to RAM? (Please have a > > look at section 2 of Documentation/power/basic-pm-debugging.txt in the newer > > kernel sources). > > I checked without X before, but forgot to unload the nvidia module, that > apparently makes a big difference, I did some numbers with > scripts/show_delta -b "Back to C". > > Nvidia and X : 32 seconds > No X (same result as booting with init=/bin/bash) : 8.3 seconds > Git kernel : 8.2 seconds > Light kernel (no sound, network card and usb drivers) : 8.17 seconds > ATI card instead of nvidia : 8.22 seconds > > I think we found the problem, I already replaced nvidia hardware in one > computer to resolve another issue. Really appreciate your help on this > issue, this resume time works pretty well for me, it was a bit > ridiculous when I could boot faster than resume. > > Is 8 seconds fairly expected?
Well, it should be a bit less than that. Usually, the resume shouldn't take more than 5 sec.
> My other computer (same ati card) boots > in about 2 seconds, but there's a lot less hardware in it (6 hd's and a > ton of usb devices in one computer, 1 hd and 1 usb device in the other).
That may matter a lot. It would be interesting to check if detaching any of those devices from the first machine helps. ;-)
> I checked cold booting with and without usb devices, my light kernel > boots to /bin/bash in 2.5 seconds, normal kernel about 7-8. But I dont > see anything about usb on resume.
Of course the USB devices are also resumed and that takes time (comparable to the boot time).
Thanks, Rafael
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