[to-be-updated] mm-vmalloc-skip-the-uninitilized-vmalloc-areas.patch removed from -mm tree

[to-be-updated] mm-vmalloc-skip-the-uninitilized-vmalloc-areas.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/vmalloc: skip the uninitilized vmalloc areas
has been removed from the -mm tree.  Its filename was
     mm-vmalloc-skip-the-uninitilized-vmalloc-areas.patch

This patch was dropped because an updated version will be merged

------------------------------------------------------
From: Baoquan He <bhe@redhat.com>
Subject: mm/vmalloc: skip the uninitilized vmalloc areas
Date: Fri, 13 Jan 2023 11:19:19 +0800

For areas allocated via vmalloc_xxx() APIs, it searches for unmapped area
to reserve and allocates new pages to map into, please see function
__vmalloc_node_range().  During the process, flag VM_UNINITIALIZED is set
in vm->flags to indicate that the pages allocation and mapping haven't
been done, until clear_vm_uninitialized_flag() is called to clear it.

For this kind of area, if VM_UNINITIALIZED is still set, let's ignore it
in vread() because pages newly allocated and being mapped in that area
only contains zero data.  reading them out by aligned_vread() is wasting
time.

Link: https://lkml.kernel.org/r/20230113031921.64716-6-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/mm/vmalloc.c~mm-vmalloc-skip-the-uninitilized-vmalloc-areas
+++ a/mm/vmalloc.c
@@ -3660,6 +3660,11 @@ long vread(char *buf, char *addr, unsign
 		if (!vm && !flags)
 			continue;
 
+		if (vm && (vm->flags & VM_UNINITIALIZED))
+			continue;
+		/* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
+		smp_rmb();
+
 		vaddr = (char *) va->va_start;
 		size = vm ? get_vm_area_size(vm) : va_size(va);
 
_

Patches currently in -mm which might be from bhe@redhat.com are

powerpc-mm-add-vm_ioremap-flag-to-the-vmalloc-area.patch
sh-mm-set-vm_ioremap-flag-to-the-vmalloc-area.patch