From: Pavel Charvat <pchar@ucw.cz>
Date: Fri, 13 Feb 2015 12:43:16 +0000 (+0000)
Subject: Mempool: mp_new(size) should not add size of chunk header before aligned to pages.
X-Git-Tag: v6.3~7
X-Git-Url: http://mj.ucw.cz/gitweb/?a=commitdiff_plain;h=497347e5c693bdb5f6c7fb5e4d4eddafcd7644c9;p=libucw.git

Mempool: mp_new(size) should not add size of chunk header before aligned to pages.

... so that mp_new(4096) allocates exactly one page, not two.
---

diff --git a/ucw/mempool.c b/ucw/mempool.c
index f9e268da..0bceb2bb 100644
--- a/ucw/mempool.c
+++ b/ucw/mempool.c
@@ -31,7 +31,8 @@ static size_t
 mp_align_size(size_t size)
 {
 #ifdef CONFIG_UCW_POOL_IS_MMAP
-  return ALIGN_TO(size + MP_CHUNK_TAIL, CPU_PAGE_SIZE) - MP_CHUNK_TAIL;
+  size = MAX(size, 64 + MP_CHUNK_TAIL);
+  return ALIGN_TO(size, CPU_PAGE_SIZE) - MP_CHUNK_TAIL;
 #else
   return ALIGN_TO(size, CPU_STRUCT_ALIGN);
 #endif