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author | Hugh Dickins <hugh@veritas.com> | 2005-10-29 18:16:23 -0700 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-10-29 21:40:40 -0700 |
commit | c74df32c724a1652ad8399b4891bb02c9d43743a (patch) | |
tree | 5a79d56fdcf7dc2053a277dbf6db7c3b339e9659 /arch/sparc/mm | |
parent | 1bb3630e89cb8a7b3d3807629c20c5bad88290ff (diff) | |
download | op-kernel-dev-c74df32c724a1652ad8399b4891bb02c9d43743a.zip op-kernel-dev-c74df32c724a1652ad8399b4891bb02c9d43743a.tar.gz |
[PATCH] mm: ptd_alloc take ptlock
Second step in pushing down the page_table_lock. Remove the temporary
bridging hack from __pud_alloc, __pmd_alloc, __pte_alloc: expect callers not
to hold page_table_lock, whether it's on init_mm or a user mm; take
page_table_lock internally to check if a racing task already allocated.
Convert their callers from common code. But avoid coming back to change them
again later: instead of moving the spin_lock(&mm->page_table_lock) down,
switch over to new macros pte_alloc_map_lock and pte_unmap_unlock, which
encapsulate the mapping+locking and unlocking+unmapping together, and in the
end may use alternatives to the mm page_table_lock itself.
These callers all hold mmap_sem (some exclusively, some not), so at no level
can a page table be whipped away from beneath them; and pte_alloc uses the
"atomic" pmd_present to test whether it needs to allocate. It appears that on
all arches we can safely descend without page_table_lock.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/sparc/mm')
0 files changed, 0 insertions, 0 deletions