linux-kernel - [PATCH] Save some bytes in mm_struct by filling holes on 64bit

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20080312142807.GA2290@bingen.suse.de>
Date:	Wed, 12 Mar 2008 15:28:07 +0100
From:	Andi Kleen <ak@...e.de>
To:	akpm@...l.org, linux-kernel@...r.kernel.org
Subject: [PATCH] Save some bytes in mm_struct by filling holes on 64bit


Save some bytes in mm_struct by filling holes

Putting int values together for better packing on 64bit 
shrinks sizeof(struct mm_struct) from 776 bytes to 760 bytes.

Signed-off-by: Andi Kleen <ak@...e.de>

Index: linux-2.6.25-rc5/include/linux/mm_types.h
===================================================================
--- linux-2.6.25-rc5.orig/include/linux/mm_types.h
+++ linux-2.6.25-rc5/include/linux/mm_types.h
@@ -172,6 +172,7 @@ struct mm_struct {
 	atomic_t mm_users;			/* How many users with user space? */
 	atomic_t mm_count;			/* How many references to "struct mm_struct" (users count as 1) */
 	int map_count;				/* number of VMAs */
+	rwlock_t		ioctx_list_lock;	/* aio lock */
 	struct rw_semaphore mmap_sem;
 	spinlock_t page_table_lock;		/* Protects page tables and some counters */
 
@@ -213,14 +214,13 @@ struct mm_struct {
 	unsigned int token_priority;
 	unsigned int last_interval;
 
+	int core_waiters;
 	unsigned long flags; /* Must use atomic bitops to access the bits */
 
 	/* coredumping support */
-	int core_waiters;
 	struct completion *core_startup_done, core_done;
 
 	/* aio bits */
-	rwlock_t		ioctx_list_lock;
 	struct kioctx		*ioctx_list;
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
 	struct mem_cgroup *mem_cgroup;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/