On 07/21/15 at 12:22pm, Yinghai Lu wrote: > On Tue, Jul 21, 2015 at 1:58 AM, Baoquan He <[email protected]> wrote: > > > Maybe system which don't need low memory is rare, only for testing? > > No, it is not rare. > > All recent intel based systems with iommu support does not need low. > > And those systems get punished by following patch: > > | commit 94fb9334182284e8e7e4bcb9125c25dc33af19d4 > | Author: Joerg Roedel <[email protected]> > | Date: Wed Jun 10 17:49:42 2015 +0200 > | > | x86/crash: Allocate enough low memory when crashkernel=high > > that reserve 256M low always. and those 256M get wasted. > > That commit should only be used to workaround some systems that > have partial iommu support. >
Since low memory does not need for some machines, how about kexec does not allocate low memory automatically, if cmdline does not specify the option ",low". User shall know well, if they specify the cmdline with option ",high". Thanks Minfei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
