[PATCH V8 1/4] mm: frontswap: swap data structure changes

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>
Subject: [PATCH V8 1/4] mm: frontswap: swap data structure changes

This first patch of four in the frontswap series makes available core
swap data structures (swap_lock, swap_list and swap_info) that are
needed by frontswap.c but we don't need to expose them to the dozens
of files that include swap.h so we create a new swapfile.h just to
extern-ify these.

Also add frontswap-related elements to swap_info_struct.  Frontswap_map
points to vzalloc'ed one-bit-per-swap-page metadata that indicates
whether the swap page is in frontswap or in the device and frontswap_pages
counts how many pages are in frontswap.

[v8: rebase to 3.0-rc4]
[v8: kamezawa.hiroyu@xxxxxxxxxxxxxx: frontswap_pages should be atomic_t]
[v8: kamezawa.hiroyu@xxxxxxxxxxxxxx: comment to clarify informational counters]
[v7: rebase to 3.0-rc3]
[v7: JBeulich@xxxxxxxxxx: add new swap struct elements only if config'd]
[v6: rebase to 3.0-rc1]
[v5: no change from v4]
[v4: rebase to 2.6.39]
Signed-off-by: Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>
Reviewed-by: Konrad Wilk <konrad.wilk@xxxxxxxxxx>
Reviewed-by: Kamezawa Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Acked-by: Jan Beulich <JBeulich@xxxxxxxxxx>
Acked-by: Seth Jennings <sjenning@xxxxxxxxxxxxxxxxxx>
Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Nitin Gupta <ngupta@xxxxxxxxxx>
Cc: Matthew Wilcox <matthew@xxxxxx>
Cc: Chris Mason <chris.mason@xxxxxxxxxx>
Cc: Rik Riel <riel@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>

--- linux/include/linux/swapfile.h	1969-12-31 17:00:00.000000000 -0700
+++ frontswap/include/linux/swapfile.h	2011-08-29 09:52:14.305755924 -0600
@@ -0,0 +1,13 @@
+#ifndef _LINUX_SWAPFILE_H
+#define _LINUX_SWAPFILE_H
+
+/*
+ * these were static in swapfile.c but frontswap.c needs them and we don't
+ * want to expose them to the dozens of source files that include swap.h
+ */
+extern spinlock_t swap_lock;
+extern struct swap_list_t swap_list;
+extern struct swap_info_struct *swap_info[];
+extern int try_to_unuse(unsigned int, bool, unsigned long);
+
+#endif /* _LINUX_SWAPFILE_H */
--- linux/include/linux/swap.h	2011-08-08 08:19:25.880690134 -0600
+++ frontswap/include/linux/swap.h	2011-08-29 10:02:53.152685666 -0600
@@ -194,6 +194,10 @@ struct swap_info_struct {
 	struct block_device *bdev;	/* swap device or bdev of swap file */
 	struct file *swap_file;		/* seldom referenced */
 	unsigned int old_block_size;	/* seldom referenced */
+#ifdef CONFIG_FRONTSWAP
+	unsigned long *frontswap_map;	/* frontswap in-use, one bit per page */
+	atomic_t frontswap_pages;	/* frontswap pages in-use counter */
+#endif
 };
 
 struct swap_list_t {

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>


[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux]     [Linux OMAP]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]