mm/swap.c: split put_compound_page()

Currently, put_compound_page() carefully handles tricky cases to avoid
racing with compound page releasing or splitting, which makes it quite
lenthy (about 200+ lines) and needs deep tab indention, which makes it
quite hard to follow and maintain.

Now based on two helpers introduced in the previous patch ("mm/swap.c:
introduce put_[un]refcounted_compound_page helpers for spliting
put_compound_page"), this patch replaces those two lengthy code paths with
these two helpers, respectively.  Also, it has some comment rephrasing.

After this patch, the put_compound_page() is very compact, thus easy to
read and maintain.

After splitting, the object file is of same size as the original one.
Actually, I've diff'ed put_compound_page()'s orginal disassemble code and
the patched disassemble code, the are 100% the same!

This fact shows that this splitting has no functional change, but it
brings readability.

This patch and the previous one blow the code by 32 lines, mostly due to
comments.

Signed-off-by: Jianyu Zhan <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Jiang Liu <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Sasha Levin <[email protected]>
Cc: Wanpeng Li <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions