x86/mm/64: Do not sync vmalloc/ioremap mappings
Remove the code to sync the vmalloc and ioremap ranges for x86-64. The
page-table pages are all pre-allocated so that synchronization is
no longer necessary.
This is a patch that already went into the kernel as:
commit 8bb9bf242d1f ("x86/mm/64: Do not sync vmalloc/ioremap mappings")
But it had to be reverted later because it unveiled a bug from:
commit 6eb82f994026 ("x86/mm: Pre-allocate P4D/PUD pages for vmalloc area")
The bug in that commit causes the P4D/PUD pages not to be correctly
allocated, making the synchronization still necessary. That issue got
fixed meanwhile upstream:
commit 995909a4e22b ("x86/mm/64: Do not dereference non-present PGD entries")
With that fix it is safe again to remove the page-table synchronization
for vmalloc/ioremap ranges on x86-64.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200814151947.26229-2-joro@8bytes.org
2 files changed
