Date: Sat, 12 Jun 2010 12:30:31 -0500 From: Brandon Gooch <jamesbrandongooch@gmail.com> To: David DEMELIER <demelier.david@gmail.com> Cc: freebsd-stable <freebsd-stable@freebsd.org>, John Baldwin <jhb@freebsd.org>, 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: <AANLkTimjGgFF7ZPrOvoKpq5lpKptgItokTZUGdJC1MBN@mail.gmail.com> In-Reply-To: <AANLkTilysocGoT8HVgwTZF02rSr_5JUdlwkFDUSAc1-l@mail.gmail.com> References: <g2mb3954bba1005031436g77215426n83ce7904e5ef321@mail.gmail.com> <AANLkTikUzurYQE7-tDNT-Sd9DaeSp2YLGwUXoupkvQSV@mail.gmail.com> <AANLkTinJuPX9CLW5RRYF8Xh8vX7uKacU9BpmX5uuFuxw@mail.gmail.com> <201006110818.27366.jhb@freebsd.org> <AANLkTilysocGoT8HVgwTZF02rSr_5JUdlwkFDUSAc1-l@mail.gmail.com>
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On Sat, Jun 12, 2010 at 12:19 PM, David DEMELIER <demelier.david@gmail.com> wrote: > 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.= com> >> 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_co= unt >>> > 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, =A0with a valu= e >>> > 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.c= pu.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. > > -- > Demelier David > Someone would have to discuss with the Release Engineering team, but it would be cool :) -Brandon
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