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author | Baoquan He <bhe@redhat.com> | 2023-02-06 11:40:18 +0300 |
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committer | Andrew Morton <akpm@linux-foundation.org> | 2023-02-10 03:51:43 +0300 |
commit | 30a7a9b17c4b0331ec67aadb4b30ff2a951b4ed5 (patch) | |
tree | 8a2210d7965eb95eded6fc8041566c9c8c972bb9 /arch/powerpc | |
parent | bba9697b42ead45687352fdd0fd498735bc4361d (diff) | |
download | linux-30a7a9b17c4b0331ec67aadb4b30ff2a951b4ed5.tar.xz |
mm/vmalloc: skip the uninitilized vmalloc areas
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
VM_UNINITIALIZED.
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/20230206084020.174506-6-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: Dan Carpenter <error27@gmail.com>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'arch/powerpc')
0 files changed, 0 insertions, 0 deletions