Re: [PATCH, RFC] panic-note: Annotation from user space for panics
Sincerely, I don't understand why we should involve the kernel to gather this kind of information when we can use other (user-space) tools, only to have all in a single report maybe? I think it's a bit weak reason to include this additional behavior in the kernel. David VomLehn ha scritto: Allows annotation of panics to include platform information. It's no big deal to collect information, but way helpful when you are collecting failure reports from a eventual base of millions of systems deployed in other people's homes. Marco -- To unsubscribe from this list: send the line unsubscribe linux-embedded in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH, RFC] panic-note: Annotation from user space for panics
On Wed, 2009-11-11 at 21:13 -0500, David VomLehn wrote: Allows annotation of panics to include platform information. It's no big deal to collect information, but way helpful when you are collecting failure reports from a eventual base of millions of systems deployed in other people's homes. I'd like to hear a bit more use case motivation on this feature. Also, why do you want more than a page? -- http://selenic.com : development and support for Mercurial and Linux -- To unsubscribe from this list: send the line unsubscribe linux-embedded in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH, RFC] panic-note: Annotation from user space for panics
David VomLehn wrote: Allows annotation of panics to include platform information. It's no big deal to collect information, but way helpful when you are collecting failure reports from a eventual base of millions of systems deployed in other people's homes. One of the biggest reasons this is an RFC is that I'm uncomfortable with putting the pseudo-file that holds the annotation information in /proc. Different layers of the software stack may drop dynamic information, such as DHCP-supplied IP addresses, in here as they come up. This means it's necessary to be able to append to the end of the annotation, so this looks much more like a real file than a sysctl file. It also has multiple lines, which doesn't look a sysctl file. Annotation can be viewed as a debug thing, so maybe it belongs in debugfs, but people seem to be doing somewhat different things with that filesystem. So, suggestions on this issue, and any others are most welcome. If there a better way to do this, I'll be happy to use it. Signed-off-by: David VomLehn dvoml...@cisco.com --- --- a/kernel/panic.c +++ b/kernel/panic.c @@ -70,6 +70,7 @@ NORET_TYPE void panic(const char * fmt, ...) vsnprintf(buf, sizeof(buf), fmt, args); va_end(args); printk(KERN_EMERG Kernel panic - not syncing: %s\n,buf); + panic_note_print(); #ifdef CONFIG_DEBUG_BUGVERBOSE dump_stack(); #endif Why hook into panic() directly like this, vs. using the panic notifier list? If you use that, and then put the data handling magic that you need into your own kernel module that knows how to interface with the reporting apps that you have, you can do the whole thing without having to alter existing code, I think. Paul. diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 30df586..bade7a1 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1045,6 +1045,14 @@ config DMA_API_DEBUG This option causes a performance degredation. Use only if you want to debug device drivers. If unsure, say N. +config PANIC_NOTE + bool Create file for user space data to be reported at panic time + default n + help + This creates a pseudo-file, named /proc/panic_note, into which + user space data can be written. If a panic occurs, the contents + of the file will be included in the failure report. + source samples/Kconfig source lib/Kconfig.kgdb -- To unsubscribe from this list: send the line unsubscribe linux-embedded in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH, RFC] panic-note: Annotation from user space for panics
On Thu, Nov 12, 2009 at 01:06:51PM -0500, Matt Mackall wrote: On Wed, 2009-11-11 at 21:13 -0500, David VomLehn wrote: Allows annotation of panics to include platform information. It's no big deal to collect information, but way helpful when you are collecting failure reports from a eventual base of millions of systems deployed in other people's homes. I'd like to hear a bit more use case motivation on this feature. Also, why do you want more than a page? Hopefully, I have addressed the first question in my previous email. As for the second, I doubt there is a need for more than a page. I just picked a value to start developing with. This is still a work in progress... http://selenic.com : development and support for Mercurial and Linux David VL -- To unsubscribe from this list: send the line unsubscribe linux-embedded in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH, RFC] panic-note: Annotation from user space for panics
On Thu, Nov 12, 2009 at 02:50:41PM -0500, Paul Gortmaker wrote: David VomLehn wrote: Allows annotation of panics to include platform information. It's no big deal to collect information, but way helpful when you are collecting failure reports from a eventual base of millions of systems deployed in other people's homes. ... Why hook into panic() directly like this, vs. using the panic notifier list? If you use that, and then put the data handling magic that you need into your own kernel module that knows how to interface with the reporting apps that you have, you can do the whole thing without having to alter existing code, I think. I agree--a panic notifier list is probably a better approach. David VL -- To unsubscribe from this list: send the line unsubscribe linux-embedded in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
