On 27.04.2011 23:12, Andi Kleen wrote: > On Wed, Apr 27, 2011 at 06:16:46PM +0200, Stefan Assmann wrote: >> BadRAM is a mechanism to exclude memory addresses (pages) from being used by >> the system. The addresses are given to the kernel via kernel command line. >> This is useful for systems with defective RAM modules, especially if the RAM >> modules cannot be replaced. >> >> command line parameter: badram=<addr>,<mask>[,...] >> >> Patterns for the command line parameter can be obtained by running Memtest86. >> In Memtest86 press "c" for configuration, select "Error Report Mode" and >> finally "BadRAM Patterns" >> >> This has already been done by Rick van Rein a long time ago but it never found >> it's way into the kernel. > > Looks good to me, except for the too verbose printks. Logging > every page this way will be very noisy for larger areas. You're right, logging every page marked would be too verbose. That's why I wrapped that logging into pr_debug. http://www.kernel.org/doc/local/pr_debug.txt This way it shouldn't bother anybody but it still could be useful in the case of debugging. However I kept the printk in the case of early allocated pages. The user should be notified of the attempt to mark a page that's already been allocated by the kernel itself. > > The mask will also only work for very simple memory interleaving > setups, so I suspect it won't work for a lot of modern systems > unless you go more fancy. > > Longer term there should be also likely a better way to specify > these pages than the kernel command line, e.g. the new persistent > store on some systems. I'd be happy to help improving and refining things for more fancy scenarios after this is done. Thanks for the feedback Andi. Stefan -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>