On Wednesday 25 July 2007 22:20, [email protected] wrote:
> On Wed, 25 Jul 2007, Len Brown wrote:
>
> > On Wednesday 25 July 2007 14:48, Linus Torvalds wrote:
> >
> >> ... ACPI now seems to select CPU hotplug. Why?
> >
> > ACPI=y SMP=y systems require SUSPEND_SMP=y for system sleep support,
> > and that requires HOTPLUG_CPU=y.
> >
> > Note that ACPI=y SMP=n systems do not need it,
> > and thus will not select HOTPLUG_CPU=y
> >
> >> That is just *broken*. Sure, if you select STR or hibernation, we need CPU
> >> hotplug, but just for picking ACPI? Why?
> >
> > My assumption is that if somebody selects CONFIG_ACPI,
> > that 99% of the time, they intend that to include support for
> > the ACPI hooks for system sleep states.
> >
> > Conversely, supporting the 1% of people who don't want it
> > isn't worth messing with the 99% who do, nor is
> > the burden of yet another config option to maintain and
> > #ifdefs in the code.
>
> so you are saying that you know better then we do what we need?
Feel free to share what you know about the benefits vs. the costs
of maintaining CONFIG_ACPI_SLEEP as a build option.
> some people configure ACPI only becouse their system won't work properly
> without it. they have no intention of ever doing a STR or hibernate.
I agree.
Further, I expect that 100% - (some people %) = 99%
If you feel that your system has been degraded
because it now includes what used to be excluded under
CONFIG_ACPI_SLEEP=n, please let me know how.
> > On UP, they'd get ACPI system sleep support 100% of the time
> > by default, but on SMP this option had become problematic.
> >
> > We used to have this:
> >
> > if ACPI
> > ...
> > config ACPI_SLEEP
> > bool "Sleep States"
> > depends on X86 && (!SMP || SUSPEND_SMP)
> > depends on PM
> > default y
> >
> > So the poster-child failure was i386/defconfig itself...
> > It couldn't support suspend to RAM because it didn't include
> > CONFIG_ACPI_SLEEP. Not trivial for a user to select it
> > when it doesn't even appear on the menu. It doesn't appear
> > because CONFIG_SUSPEND_SMP isn't enabled, but that doesn't
> > appear either -- because CONFIG_HOTPLUG_CPU isn't selected.
>
> so have something like
>
> config ACPI_SLEEP
> select HOTPLUG_CPU if X86 && SMP
> select SUSPEND_SMP if X86 && SMP
>
> instead of makeing it dependant on ACPI.
If more config options where better, then this
would indeed be an improvement over 2.6.22.
But more config options isn't better -- except for "some people":-)
thanks.
-Len
> > Most users don't want that.
> >
> > So today we have this:
> >
> > menuconfig ACPI
> > ...
> > select HOTPLUG_CPU if X86 && SMP
> > select SUSPEND_SMP if X86 && SMP
> >
> > Which I think leads to fewer surprises, and less complicated code.
> > (even though using select itself is fraught with peril:-)
> >
> > thanks,
> > -Len
> >
> > -
> > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> > the body of a message to [email protected]
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > Please read the FAQ at http://www.tux.org/lkml/
> >
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
