On Wed, 06 Feb 2008 21:32:55 -0800 Max Krasnyansky <[EMAIL PROTECTED]> wrote:
> Linus, please pull CPU isolation extensions from > > git://git.kernel.org/pub/scm/linux/kernel/git/maxk/cpuisol-2.6.git for-linus The feature as a whole seems useful, and I don't actually oppose the merge based on what I see here. As long as you're really sure that cpusets are inappropriate (and bear in mind that Paul has a track record of being wrong on this :)). But I see a few glitches - There are two separate and identical implementations of cpu_unusable(cpu). Please do it once, in a header, preferably with C function, not macros. - The Kconfig help is a bit scraggly: +config CPUISOL_STOPMACHINE + bool "Do not halt isolated CPUs with Stop Machine (HIGHLY EXPERIMENTAL)" + depends on CPUISOL && STOP_MACHINE && EXPERIMENTAL + help + If this option is enabled kernel will not halt isolated CPUs when Stop Machine "the kernel" text is too wide + is triggered. + Stop Machine is currently only used by the module insertion and removal logic. + Please note that at this point this feature is highly experimental and maybe + dangerous. It is not known to really brake anything but can potentially + introduce an instability. s/maybe/may be/ s/brake/break/ Neither this text, nor the changelog nor the code comments tell us what the potential instability with stopmachine *is*? Or maybe I missed it. - Adding new sysfs files without updating Documentation/ABI/ makes Greg cry. - Why is cpu_isolated_map exported to modules? Just for api consistency, it appears? pre-existing problems: - isolated_cpu_setup() has an on-stack array of NR_CPUS integers. This will consume 4k of stack on ia64 (at least). We'll just squeak through for a ittle while, but this needs to be fixed. Just move it into __initdata. - isolated_cpu_setup() expects that the user can provide an up-to-1024 character kernel boot parameter. Is this reasonable given cpu command line limits, and given that NR_CPUS will surely grow beyond 1024 in the future? -- 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/