Messages in this thread | | | Date | Wed, 11 Jan 2012 15:28:11 +0800 | From | Chen Gong <> | Subject | Re: [RFC][PATCH v4 -next 1/4] Move kmsg_dump(KMSG_DUMP_PANIC) below smp_send_stop() |
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于 2012/1/11 4:29, Seiji Aguchi 写道: > >> I agree with you. How about adding macros or something like WARN_ON(XX_ARCH) or >> Kconfig to limit its scope? > > Thank you for giving me your idea. > Your suggestions above will work for me because I'm a x86 user. > If Tony agrees to it, I can update my patch. > > But, I'm hesitating to add WARN_ON() or change Kconfig only for specific arch > because pstore aims for generic interface and this is related to its design. > Also, ramoops is going to use pstore now. It doesn't depend on x86. > I'm worried that ramoops users will complain about this change. > > So, I think a reasonable solution at this time is just adding some explanations > about smp_send_stop() to documentation as follows. > > Users can use pstore with their own responsibility and ask developers > if smp_send_stop() is reliable enough in panic situation on architecture they want to run. > > What do you think? > > --- > Documentation/ABI/testing/pstore | 8 ++++++++ > 1 files changed, 8 insertions(+), 0 deletions(-) > > diff --git a/Documentation/ABI/testing/pstore b/Documentation/ABI/testing/pstore > index ff1df4e..5583729 100644 > --- a/Documentation/ABI/testing/pstore > +++ b/Documentation/ABI/testing/pstore > @@ -11,6 +11,14 @@ Description: Generic interface to platform dependent persistent storage. > of the console log is captured, but other interesting > data can also be saved. > > + In case of panic, pstore is invoked after smp_send_stop() > + ,a function call stopping other cpus, so that we can get > + logs simpler and cleaner with just one running cpu. > + > + As for x86, smp_send_stop() is reliable enough to work in > + panic situation. But we are not guaranteed that it works > + reliably on other architectures. > + > # mount -t pstore -o kmsg_bytes=8000 - /dev/pstore > > $ ls -l /dev/pstore
The explanation is great. but In my opinion, I still insist that a WARN_ON() is necessary. What do you think, Tony and Don? -- 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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