Message ID | 022b1a5e-4121-6bae-f07c-4ad5eac12481@suse.com (mailing list archive) |
---|---|
Headers | show |
Series | xen/x86: PV boot speedup | expand |
On 9/30/21 8:33 AM, Jan Beulich wrote: > The observed (by the human eye) performance difference of early boot > between native and PV-on-Xen was just too large to not look into. As > it turns out, gaining performance back wasn't all that difficult. > > While the series (re)introduces a small number of PTWR emulations on > the boot path (from phys_pte_init()), there has been a much larger > number of them post-boot. Hence I think if this was of concern, the > post-boot instances would want eliminating first. > > Some of the later changes aren'r directly related to the main goal of > the series; these address aspects noticed while doing the investigation. > > 1: streamline set_pte_mfn() > 2: restore (fix) xen_set_pte_init() behavior > 3: adjust xen_set_fixmap() > 4: adjust handling of the L3 user vsyscall special page table > 5: there's no highmem anymore in PV mode > 6: restrict PV Dom0 identity mapping For the series: Reviewed-by: Boris Ostrovsky <boris.ostrovksy@oracle.com>
On 9/30/21 8:33 AM, Jan Beulich wrote: > The observed (by the human eye) performance difference of early boot > between native and PV-on-Xen was just too large to not look into. As > it turns out, gaining performance back wasn't all that difficult. > > While the series (re)introduces a small number of PTWR emulations on > the boot path (from phys_pte_init()), there has been a much larger > number of them post-boot. Hence I think if this was of concern, the > post-boot instances would want eliminating first. > > Some of the later changes aren'r directly related to the main goal of > the series; these address aspects noticed while doing the investigation. > > 1: streamline set_pte_mfn() > 2: restore (fix) xen_set_pte_init() behavior > 3: adjust xen_set_fixmap() > 4: adjust handling of the L3 user vsyscall special page table > 5: there's no highmem anymore in PV mode > 6: restrict PV Dom0 identity mapping Applied to for-linus-5.16 -boris