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.
Yeah, you are right. > > 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. Those big servers mostly has hardware iommu. But they still can enable swiotlb suport. Then low memory is needed. > > Yinghai -- 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/
