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


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@suse.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;

             reply	other threads:[~2008-03-12 14:28 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-12 14:28 Andi Kleen [this message]
2008-03-12 18:05 ` [PATCH] Save some bytes in mm_struct by filling holes on 64bit Andrew Morton
2008-03-12 18:38   ` Andi Kleen
2008-03-13 16:40 ` Lennart Sorensen

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