> On Aug 1, 2018, at 11:33 AM, Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote: > > On 1 August 2018 at 19:07, Jeffrey Hugo <jhugo@xxxxxxxxxxxxxx> wrote: >> On 8/1/2018 10:27 AM, Eric Snowberg wrote: >>> Once EBS is called, there isn’t enough room available for the new memory >>> map on a very large system (do to the memory that was previously allocated >>> in exit_boot_func). >>> >>> The race condition that exists between priv_func and the call to EBS will >>> be taken care of by the existing code, thru the slack slots. >> >> >> Now I'm slightly confused. There isn't an issue because of slack slots? >> >> I'm kind of wondering if our assumption that 8 slots would be enough is not >> invalid, and therefore we need to increase that number. I hate kicking the >> can down the road like that, but as discussed in 2016, there doesn't seem to >> be a good alternative. >> > > But why does alloc_e820ext have to be deferred to the last minute? I didn’t understand that either. If it was done earlier, I assume there would not be a problem. Our tests show any kernel prior to Commit d64934019f6c ("x86/efi: Use efi_exit_boot_services()”) will boot successfully. The first "goto get_map" that was removed from the previous exit_boot insured their was enough room for the memory map when EBS was called. Which would you rather see done? Increase the slack number or move the e820 code? I can look at doing either if you'd like. -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html