Messages in this thread | | | Date | Wed, 7 Oct 2009 04:03:16 -0700 | Subject | Re: [BISECTED] "conservative" cpufreq governor broken | From | Steven Noonan <> |
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On Wed, Oct 7, 2009 at 3:42 AM, Thomas Gleixner <tglx@linutronix.de> wrote: > On Wed, 7 Oct 2009, Eero Nurkkala wrote: >> For some reason, this path is taken: >> if (ts->nohz_mode == NOHZ_MODE_INACTIVE) >> goto end; > > Well, probably because the machine never switched to NOHZ :) > >> > Also, this fix should probably be passed on to Greg K. H. (so it goes >> > in 2.6.31-stable) as well as Ingo Molnar (so it goes into -tip, and >> > hopefully to Linus for 2.6.32). Both CC'd. > > Don't worry, it'll go the right way. No need to cc the world and some > more :) >
Sorry if it's not kosher. I was told that when dealing with a bisection you should CC: 1. those involved with a bisected patch (the Signed-off-by people), 2. those responsible for the affected subsystem (doing an author check via script[1]), 3. and those to whom a fix should be passed on to.
Any tips so I don't bug the wrong people (or too many people) in the future?
[1] http://www.uplinklabs.net/~tycho/linux/scripts/git-authors-email.sh (credits to Ingo for making this one. It's handy)
>> >> From: Eero Nurkkala <ext-eero.nurkkala@nokia.com> >> Date: Wed, 7 Oct 2009 11:54:26 +0300 >> Subject: [PATCH] NOHZ: update idle state properly >> >> Commit f2e21c9610991e95621a81407cdbab881226419b >> had unfortunate side effects with cpufreq governors on >> some systems. >> >> If NOHZ_MODE_INACTIVE was set, ts->inidle was not being >> set. Then, all subsequent calls from irq_exit() bypassed >> calls to tick_nohz_start_idle() which resulted in wrong >> information passed to cpufreq governors. Fix this by >> updating the state of ts->inidle where it fits the best. > > Hmm, nasty that code silently relies on NOHZ functionality even when > NOHZ is not active. That needs a big fat comment at least. > > Nice detective work though ! > > Thanks, > > tglx > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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