Talk:Hardware Power Domains: Difference between revisions
JordanCrouse (talk | contribs) (S2 is uninteresting) |
JordanCrouse (talk | contribs) (C1 test) |
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= Power Domain Discussion = |
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== No support for optional ACPI Sleep state S2 == |
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* S2 is uninteresting. IMHO - its a vague state literally defined as "higher latency then S1 but lower latency then S3". Not sure if your itention here is to mention that S2 *should* |
* S2 is uninteresting. IMHO - its a vague state literally defined as "higher latency then S1 but lower latency then S3". Not sure if your itention here is to mention that S2 *should* |
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be supported, or just commenting that it isn't. - [[User:JordanCrouse|JordanCrouse]] ([[User talk:JordanCrouse|Talk to me!]]) 18:58, 12 September 2006 (EDT) |
be supported, or just commenting that it isn't. - [[User:JordanCrouse|JordanCrouse]] ([[User talk:JordanCrouse|Talk to me!]]) 18:58, 12 September 2006 (EDT) |
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== C1 Test == |
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This confused me for a second - what you're talking about is really more of a poor man's S1 - turning off pratically everything we can, turn off the PIT, |
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and then enable wakeup devices and go to a hlt. A more correct name might be low-latency S1, because it will be slower then a C state transition (obivously) but it should be faster then a S1 transition. |
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This is quite similar to a tickless system, except that we turn off more devices. The only question is - how quickly can we turn off and turn on the un-needed devices, and does that latency fit within the average idle timesice of a nominally busy kernel? I believe that we can measure the average length between timeouts in the kernel with Systemtap - that would be useful information |
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to have. If we can make this all fit - it would be a heck of a cool thing. - [[User:JordanCrouse|JordanCrouse]] ([[User talk:JordanCrouse|Talk to me!]]) 19:16, 12 September 2006 (EDT) |
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Revision as of 23:16, 12 September 2006
Power Domain Discussion
No support for optional ACPI Sleep state S2
- S2 is uninteresting. IMHO - its a vague state literally defined as "higher latency then S1 but lower latency then S3". Not sure if your itention here is to mention that S2 *should*
be supported, or just commenting that it isn't. - JordanCrouse (Talk to me!) 18:58, 12 September 2006 (EDT)
C1 Test
This confused me for a second - what you're talking about is really more of a poor man's S1 - turning off pratically everything we can, turn off the PIT, and then enable wakeup devices and go to a hlt. A more correct name might be low-latency S1, because it will be slower then a C state transition (obivously) but it should be faster then a S1 transition.
This is quite similar to a tickless system, except that we turn off more devices. The only question is - how quickly can we turn off and turn on the un-needed devices, and does that latency fit within the average idle timesice of a nominally busy kernel? I believe that we can measure the average length between timeouts in the kernel with Systemtap - that would be useful information to have. If we can make this all fit - it would be a heck of a cool thing. - JordanCrouse (Talk to me!) 19:16, 12 September 2006 (EDT)