[PATCH RFC] mm: simplify frontswap_init()
From: Cesar Eduardo Barros <hidden>
Date: 2012-10-30 23:13:09
Also in:
lkml
Subsystem:
memory management, memory management - swap, staging subsystem, the rest, xen hypervisor interface · Maintainers:
Andrew Morton, Chris Li, Kairui Song, Greg Kroah-Hartman, Linus Torvalds, Juergen Gross, Stefano Stabellini
The function frontswap_init() uses the passed parameter only to check for the presence of the frontswap_map. It is also passed down to frontswap_ops.init(), but all implementations of it in the kernel ignore the parameter. Do the check for frontswap_map in the caller instead and remove the parameter from frontswap_init() and frontswap_ops.init(). Also, __frontswap_init() was exported, but its only caller (via an inline function) is mm/swapfile.c, which cannot be built as a module. Remove the unnecessary export. Signed-off-by: Cesar Eduardo Barros <redacted> --- Not even compile tested, just a quick patch to show what I was thinking of, but feel free to apply if you think it is good. I might write another patch to move it outside the lock later, but I would have to read the frontswap code more carefully first. drivers/staging/ramster/zcache-main.c | 2 +- drivers/staging/zcache/zcache-main.c | 2 +- drivers/xen/tmem.c | 2 +- include/linux/frontswap.h | 8 ++++---- mm/frontswap.c | 10 ++-------- mm/swapfile.c | 3 ++- 6 files changed, 11 insertions(+), 16 deletions(-)
diff --git a/drivers/staging/ramster/zcache-main.c b/drivers/staging/ramster/zcache-main.c
index a09dd5c..b3f01c9 100644
--- a/drivers/staging/ramster/zcache-main.c
+++ b/drivers/staging/ramster/zcache-main.c@@ -1610,7 +1610,7 @@ static void zcache_frontswap_flush_area(unsigned type) } } -static void zcache_frontswap_init(unsigned ignored) +static void zcache_frontswap_init(void) { /* a single tmem poolid is used for all frontswap "types" (swapfiles) */ if (zcache_frontswap_poolid < 0)
diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index 52b43b7..cb67635 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c@@ -1903,7 +1903,7 @@ static void zcache_frontswap_flush_area(unsigned type) } } -static void zcache_frontswap_init(unsigned ignored) +static void zcache_frontswap_init(void) { /* a single tmem poolid is used for all frontswap "types" (swapfiles) */ if (zcache_frontswap_poolid < 0)
diff --git a/drivers/xen/tmem.c b/drivers/xen/tmem.c
index 144564e..7156ff0 100644
--- a/drivers/xen/tmem.c
+++ b/drivers/xen/tmem.c@@ -343,7 +343,7 @@ static void tmem_frontswap_flush_area(unsigned type) (void)xen_tmem_flush_object(pool, oswiz(type, ind)); } -static void tmem_frontswap_init(unsigned ignored) +static void tmem_frontswap_init(void) { struct tmem_pool_uuid private = TMEM_POOL_PRIVATE_UUID;
diff --git a/include/linux/frontswap.h b/include/linux/frontswap.h
index 3044254..6374c80 100644
--- a/include/linux/frontswap.h
+++ b/include/linux/frontswap.h@@ -6,7 +6,7 @@ #include <linux/bitops.h> struct frontswap_ops { - void (*init)(unsigned); + void (*init)(void); int (*store)(unsigned, pgoff_t, struct page *); int (*load)(unsigned, pgoff_t, struct page *); void (*invalidate_page)(unsigned, pgoff_t);
@@ -22,7 +22,7 @@ extern void frontswap_writethrough(bool); #define FRONTSWAP_HAS_EXCLUSIVE_GETS extern void frontswap_tmem_exclusive_gets(bool); -extern void __frontswap_init(unsigned type); +extern void __frontswap_init(void); extern int __frontswap_store(struct page *page); extern int __frontswap_load(struct page *page); extern void __frontswap_invalidate_page(unsigned, pgoff_t);
@@ -120,10 +120,10 @@ static inline void frontswap_invalidate_area(unsigned type) __frontswap_invalidate_area(type); } -static inline void frontswap_init(unsigned type) +static inline void frontswap_init(void) { if (frontswap_enabled) - __frontswap_init(type); + __frontswap_init(); } #endif /* _LINUX_FRONTSWAP_H */
diff --git a/mm/frontswap.c b/mm/frontswap.c
index 2890e67..d13661b 100644
--- a/mm/frontswap.c
+++ b/mm/frontswap.c@@ -115,16 +115,10 @@ EXPORT_SYMBOL(frontswap_tmem_exclusive_gets); /* * Called when a swap device is swapon'd. */ -void __frontswap_init(unsigned type) +void __frontswap_init(void) { - struct swap_info_struct *sis = swap_info[type]; - - BUG_ON(sis == NULL); - if (sis->frontswap_map == NULL) - return; - frontswap_ops.init(type); + frontswap_ops.init(); } -EXPORT_SYMBOL(__frontswap_init); static inline void __frontswap_clear(struct swap_info_struct *sis, pgoff_t offset) {
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 088daf4..28c26bd 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c@@ -1479,7 +1479,8 @@ static void enable_swap_info(struct swap_info_struct *p, int prio, { spin_lock(&swap_lock); _enable_swap_info(p, prio, swap_map, frontswap_map); - frontswap_init(p->type); + if (frontswap_map) + frontswap_init(); spin_unlock(&swap_lock); }
--
1.7.11.7
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