From 803d0c8351b47b72b8b018457a33b342557b90a2 Mon Sep 17 00:00:00 2001 From: Cesar Eduardo Barros Date: Tue, 22 Mar 2011 16:33:14 -0700 Subject: [PATCH] sys_swapon: use vzalloc() instead of vmalloc/memset This patch series refactors the sys_swapon function. sys_swapon is currently a very large function, with 313 lines (more than 12 25-line screens), which can make it a bit hard to read. This patch series reduces this size by half, by extracting large chunks of related code to new helper functions. One of these chunks of code was nearly identical to the part of sys_swapoff which is used in case of a failure return from try_to_unuse(), so this patch series also makes both share the same code. As a side effect of all this refactoring, the compiled code gets a bit smaller (from v1 of this patch series): text data bss dec hex filename 14012 944 276 15232 3b80 mm/swapfile.o.before 13941 944 276 15161 3b39 mm/swapfile.o.after This patch: Use vzalloc() instead of vmalloc/memset. Signed-off-by: Cesar Eduardo Barros Tested-by: Eric B Munson Acked-by: Eric B Munson Reviewed-by: Pekka Enberg Reviewed-by: Jesper Juhl Reviewed-by: KAMEZAWA Hiroyuki Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swapfile.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index 6d6d28c0a72f..99eb5048b7a8 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2047,13 +2047,12 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) goto bad_swap; /* OK, set up the swap map and apply the bad block list */ - swap_map = vmalloc(maxpages); + swap_map = vzalloc(maxpages); if (!swap_map) { error = -ENOMEM; goto bad_swap; } - memset(swap_map, 0, maxpages); nr_good_pages = maxpages - 1; /* omit header page */ for (i = 0; i < swap_header->info.nr_badpages; i++) { -- GitLab