Re: [PATCH RESEND v2] docs: x86: Remove obsolete information about x86_64 vmalloc() faulting

Joerg Roedel [off-list ref] writes:

On Wed, Aug 18, 2021 at 03:01:23PM -0700, Peilin Ye wrote:

quoted

From: Peilin Ye <redacted>

x86_64 vmalloc() mappings are no longer "synchronized" among page tables
via faulting since commit 6eb82f994026 ("x86/mm: Pre-allocate P4D/PUD
pages for vmalloc area"), since the corresponding P4D or PUD pages are
now preallocated at boot, by preallocate_vmalloc_pages().  Drop the
"lazily synchronized" description for less confusion.

While this file is x86_64-specific, it is worth noting that things are
different for x86_32, where vmalloc()-related changes to `init_mm.pgd` are
synchronized to all page tables in the system during runtime, via
arch_sync_kernel_mappings().  Unfortunately, this synchronization is
subject to race condition, which is further handled via faulting, see
vmalloc_fault().  See commit 4819e15f740e ("x86/mm/32: Bring back vmalloc
faulting on x86_32") for more details.

Reviewed-by: Muchun Song <redacted>
Signed-off-by: Peilin Ye <redacted>

Reviewed-by: Joerg Roedel <redacted>

Applied, thanks.

jon