Date: Sat, 12 Jun 2010 19:19:41 +0200 From: David DEMELIER <demelier.david@gmail.com> To: John Baldwin <jhb@freebsd.org> Cc: freebsd-stable <freebsd-stable@freebsd.org>, Brandon Gooch <jamesbrandongooch@gmail.com>, Giovanni Trematerra <giovanni.trematerra@gmail.com>, avg@freebsd.org, Attilio Rao <attilio@freebsd.org>, kib@freebsd.org, Rui Paulo <rpaulo@freebsd.org>, jkim@freebsd.org Subject: Re: Kernel panic when unpluggin AC adaptor Message-ID: <AANLkTilysocGoT8HVgwTZF02rSr_5JUdlwkFDUSAc1-l@mail.gmail.com> In-Reply-To: <201006110818.27366.jhb@freebsd.org> References: <g2mb3954bba1005031436g77215426n83ce7904e5ef321@mail.gmail.com> <AANLkTikUzurYQE7-tDNT-Sd9DaeSp2YLGwUXoupkvQSV@mail.gmail.com> <AANLkTinJuPX9CLW5RRYF8Xh8vX7uKacU9BpmX5uuFuxw@mail.gmail.com> <201006110818.27366.jhb@freebsd.org>
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2010/6/11 John Baldwin <jhb@freebsd.org>: > On Friday 11 June 2010 6:27:48 am Giovanni Trematerra wrote: >> On Thu, Jun 10, 2010 at 10:58 PM, Giovanni Trematerra >> <giovanni.trematerra@gmail.com> wrote: >> > On Tue, May 4, 2010 at 6:35 PM, David DEMELIER <demelier.david@gmail.c= om> > wrote: >> >> Good news ! It worked, check the picture here : >> >> >> >> http://img63.imageshack.us/img63/4244/dsc00361g.jpg >> >> >> > >> > Into the file sys/dev/acpica/acpi_cpu.c at the end of acpi_cpu_notify >> > (a per cpu notification handler), called when _CST objects changing, >> > global cpu_cx_count is set to the greatest value of all sc->cpu_cx_cou= nt >> > per-cpu variables. That could result in a panic as David reported, >> > because that lets to invoke acpi_cpu_global_cx_lowest_sysctl from >> > /etc/rc.d/power_profile, when AC adapter is unplugged, =C2=A0with a va= lue >> > that not all the CPUs could handle in the acpi_cpu_idle. >> > The patch also change global cpu_cx_lowest according to new value of >> > global cpu_cx_count if needed. >> > >> > David Demelier made a great work to test every patch I sent him >> > to identify the source of the problem. >> > >> > Please, let me know your comments and possibly commit the patch >> > if you think is good enough. >> >> As jhb@ pointed me out in private with the previous patch a CPU could >> never enter in the >> lowest Cx-state even if it gained. >> So I'd like to propose this new solution. >> When hw.acpi.cpu.cx_lowest sysctl is set, the global handler in >> sys/dev/acpi_cpu.c >> will set the greatest sc->cpu_cx_lowest value supported by the CPU and >> not the same >> value for all CPUs. >> Later, when CPU, possibly gain new Cx-states, the acpi_cpu_notify >> handler will set >> sc->cpu_cx_lowest accordingly with global cx_lowest and the Cx-states >> supported by >> the CPU. >> >> Now I think that /etc/rc.d/power_profile script has a problem but that >> is a different story. >> The script select the lowest_value only querying cx-states of the dev.cp= u.0. >> If different CPUs may have different Cx-states, the script should use >> as lowest_value the >> lowest value between all the CPUs. > > Yes. > >> Please, let me know your comments and possibly commit the patch >> if you think is good enough. > > I think this is a good compromise for now. > > -- > John Baldwin > Thanks for Giovanni's patience and work, he made a lot of research to solve this little problem :-). Is there a chance that this patch appears in 8.1-RELEASE ? Kind regards. --=20 Demelier David
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