Tim Bird <tim.bird@xxxxxxxxxxx> writes: > Eric W. Biederman wrote: >> Matt Mackall <mpm@xxxxxxxxxxx> writes: >> >>> As much as I like kexec, it loses on memory footprint by about 100x. >>> It's not appropriate for all use cases, especially things like >>> consumer-grade wireless access points and phones. >> >> In general I agree. The cost of a second kernel and initrd can be >> prohibitive in the smallest systems, and if you do a crash capture >> with using a standalone app that is reinventing the wheel. >> >> That said. I can happily run kdump with only 16M-20M reserved. >> So on many systems the cost is affordable. > > Understood. On some of my systems, the memory budget for the > entire system is 10M. On most systems I work with, it is a > struggle to reserve even 64K for this feature. crash_kexec is really a glorified jump. It is possible to do a lot in 64K with a standalone application. If reliable capture of kernel crashes is desirable to an embedded NAND device I expect a semi-general purpose dedicated application for capturing at least dmesg from the crashed kernel and write it to a file on a NAND filesystem could be worth someones time. On general purpose hardware we use a kernel and an initrd simply to reduce the development work of supporting everything and the kitchen sink. My impression is that embedded systems can afford a little more setup time, and a custom compilation, and that the hardware you would like to store things too is much more common. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
