On 23.06.2011 16:12, Matthew Garrett wrote: > On Thu, Jun 23, 2011 at 04:08:32PM +0200, Stefan Assmann wrote: >> On 23.06.2011 15:39, Matthew Garrett wrote: >>> Would it be more reasonable to do this in the bootloader? You'd ideally >>> want this to be done as early as possible in order to avoid awkward >>> situations like your ramdisk ending up in the bad RAM area. >> >> Not sure what exactly you are suggesting here. The kernel somehow needs >> to know what memory areas to avoid so we supply this information via >> kernel command line. >> What the bootloader could do is to allow the kernel/initrd to be loaded >> at an alternative address. That's briefly mentioned in the BadRAM >> Documentation as well. Is that what you mean or am I missing something? > > For EFI booting we just hand an e820 map to the kernel. It ought to be > easy enough to add support for that to the 16-bit entry point as well. > Then the bootloader just needs to construct an e820 map of its own. I > think grub2 actually already has some support for this. The advantage of > this approach is that the knowledge of bad memory only has to exist in > one place (ie, the bootloader) - the kernel can remain blisfully > unaware. > According to Rick's reply in this thread a damaged row in a DIMM can easily cause a few thousand entries in the e820 table because it doesn't handle patterns. So the question I'm asking is, is it acceptable to have an e820 table with thousands maybe ten-thousands of entries? I really have no idea of the implications, maybe somebody else can comment on that. Stefan -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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>