diff mbox series

[1/7] mm/zswap: make sure each swapfile always have zswap rb-tree

Message ID 20231206-zswap-lock-optimize-v1-1-e25b059f9c3a@bytedance.com (mailing list archive)
State New
Headers show
Series mm/zswap: optimize the scalability of zswap rb-tree | expand

Commit Message

Chengming Zhou Dec. 6, 2023, 9:46 a.m. UTC 
Not all zswap interfaces can handle the absence of the zswap rb-tree,
actually only zswap_store() has handled it for now.

To make things simple, we make sure each swapfile always have the
zswap rb-tree prepared before being enabled and used. The preparation
is unlikely to fail in practice, this patch just make it explicit.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
---
 include/linux/zswap.h |  4 ++--
 mm/swapfile.c         | 10 +++++++---
 mm/zswap.c            |  7 ++++---
 3 files changed, 13 insertions(+), 8 deletions(-)

Comments

kernel test robot Dec. 8, 2023, 3:17 p.m. UTC | #1 
Hi Chengming,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 0f5f12ac05f36f117e793656c3f560625e927f1b]

url:    https://github.com/intel-lab-lkp/linux/commits/Chengming-Zhou/mm-zswap-make-sure-each-swapfile-always-have-zswap-rb-tree/20231206-174717
base:   0f5f12ac05f36f117e793656c3f560625e927f1b
patch link:    https://lore.kernel.org/r/20231206-zswap-lock-optimize-v1-1-e25b059f9c3a%40bytedance.com
patch subject: [PATCH 1/7] mm/zswap: make sure each swapfile always have zswap rb-tree
config: i386-buildonly-randconfig-002-20231208 (https://download.01.org/0day-ci/archive/20231208/202312082309.xvC0Rdd9-lkp@intel.com/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231208/202312082309.xvC0Rdd9-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202312082309.xvC0Rdd9-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from arch/x86/kernel/asm-offsets.c:9:
   In file included from include/linux/crypto.h:17:
   In file included from include/linux/slab.h:16:
   In file included from include/linux/gfp.h:7:
   In file included from include/linux/mmzone.h:25:
>> include/linux/zswap.h:53:43: warning: non-void function does not return a value [-Wreturn-type]
   static inline int zswap_swapon(int type) {}
                                             ^
   1 warning generated.
--
   In file included from arch/x86/mm/pat/set_memory.c:6:
   In file included from include/linux/highmem.h:5:
   In file included from include/linux/fs.h:13:
   In file included from include/linux/list_lru.h:14:
   In file included from include/linux/xarray.h:15:
   In file included from include/linux/gfp.h:7:
   In file included from include/linux/mmzone.h:25:
>> include/linux/zswap.h:53:43: warning: non-void function does not return a value [-Wreturn-type]
   static inline int zswap_swapon(int type) {}
                                             ^
   arch/x86/mm/pat/set_memory.c:217:1: warning: unused function 'within_inclusive' [-Wunused-function]
   within_inclusive(unsigned long addr, unsigned long start, unsigned long end)
   ^
   2 warnings generated.
--
   In file included from arch/x86/kernel/asm-offsets.c:9:
   In file included from include/linux/crypto.h:17:
   In file included from include/linux/slab.h:16:
   In file included from include/linux/gfp.h:7:
   In file included from include/linux/mmzone.h:25:
>> include/linux/zswap.h:53:43: warning: non-void function does not return a value [-Wreturn-type]
   static inline int zswap_swapon(int type) {}
                                             ^
   1 warning generated.


vim +53 include/linux/zswap.h

    51	
    52	static inline void zswap_invalidate(int type, pgoff_t offset) {}
  > 53	static inline int zswap_swapon(int type) {}
    54	static inline void zswap_swapoff(int type) {}
    55	static inline void zswap_memcg_offline_cleanup(struct mem_cgroup *memcg) {}
    56	static inline void zswap_lruvec_state_init(struct lruvec *lruvec) {}
    57	static inline void zswap_page_swapin(struct page *page) {}
    58	#endif
    59
Chengming Zhou Dec. 8, 2023, 3:45 p.m. UTC | #2 
On 2023/12/8 23:17, kernel test robot wrote:
> Hi Chengming,
> 
> kernel test robot noticed the following build warnings:
> 
> [auto build test WARNING on 0f5f12ac05f36f117e793656c3f560625e927f1b]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Chengming-Zhou/mm-zswap-make-sure-each-swapfile-always-have-zswap-rb-tree/20231206-174717
> base:   0f5f12ac05f36f117e793656c3f560625e927f1b
> patch link:    https://lore.kernel.org/r/20231206-zswap-lock-optimize-v1-1-e25b059f9c3a%40bytedance.com
> patch subject: [PATCH 1/7] mm/zswap: make sure each swapfile always have zswap rb-tree
> config: i386-buildonly-randconfig-002-20231208 (https://download.01.org/0day-ci/archive/20231208/202312082309.xvC0Rdd9-lkp@intel.com/config)
> compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231208/202312082309.xvC0Rdd9-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202312082309.xvC0Rdd9-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):
> 
>    In file included from arch/x86/kernel/asm-offsets.c:9:
>    In file included from include/linux/crypto.h:17:
>    In file included from include/linux/slab.h:16:
>    In file included from include/linux/gfp.h:7:
>    In file included from include/linux/mmzone.h:25:
>>> include/linux/zswap.h:53:43: warning: non-void function does not return a value [-Wreturn-type]
>    static inline int zswap_swapon(int type) {}

Ah, will fix to return 0 when !CONFIG_ZSWAP here.

Thanks!
kernel test robot Dec. 8, 2023, 4:45 p.m. UTC | #3 
Hi Chengming,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 0f5f12ac05f36f117e793656c3f560625e927f1b]

url:    https://github.com/intel-lab-lkp/linux/commits/Chengming-Zhou/mm-zswap-make-sure-each-swapfile-always-have-zswap-rb-tree/20231206-174717
base:   0f5f12ac05f36f117e793656c3f560625e927f1b
patch link:    https://lore.kernel.org/r/20231206-zswap-lock-optimize-v1-1-e25b059f9c3a%40bytedance.com
patch subject: [PATCH 1/7] mm/zswap: make sure each swapfile always have zswap rb-tree
config: i386-randconfig-012-20231208 (https://download.01.org/0day-ci/archive/20231209/202312090030.s5y0gXnv-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231209/202312090030.s5y0gXnv-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202312090030.s5y0gXnv-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from include/linux/mmzone.h:25,
                    from include/linux/gfp.h:7,
                    from include/linux/slab.h:16,
                    from include/linux/crypto.h:17,
                    from arch/x86/kernel/asm-offsets.c:9:
   include/linux/zswap.h: In function 'zswap_swapon':
>> include/linux/zswap.h:53:1: warning: no return statement in function returning non-void [-Wreturn-type]
      53 | static inline int zswap_swapon(int type) {}
         | ^~~~~~
--
   In file included from include/linux/mmzone.h:25,
                    from include/linux/gfp.h:7,
                    from include/linux/umh.h:4,
                    from include/linux/kmod.h:9,
                    from include/linux/module.h:17,
                    from drivers/clk/clkdev.c:9:
   include/linux/zswap.h: In function 'zswap_swapon':
>> include/linux/zswap.h:53:1: warning: no return statement in function returning non-void [-Wreturn-type]
      53 | static inline int zswap_swapon(int type) {}
         | ^~~~~~
   drivers/clk/clkdev.c: In function 'vclkdev_alloc':
   drivers/clk/clkdev.c:173:17: warning: function 'vclkdev_alloc' might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
     173 |                 vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
         |                 ^~~~~~~~~~
--
   In file included from include/linux/mmzone.h:25,
                    from include/linux/gfp.h:7,
                    from include/linux/slab.h:16,
                    from include/linux/crypto.h:17,
                    from arch/x86/kernel/asm-offsets.c:9:
   include/linux/zswap.h: In function 'zswap_swapon':
>> include/linux/zswap.h:53:1: warning: no return statement in function returning non-void [-Wreturn-type]
      53 | static inline int zswap_swapon(int type) {}
         | ^~~~~~


vim +53 include/linux/zswap.h

    51	
    52	static inline void zswap_invalidate(int type, pgoff_t offset) {}
  > 53	static inline int zswap_swapon(int type) {}
    54	static inline void zswap_swapoff(int type) {}
    55	static inline void zswap_memcg_offline_cleanup(struct mem_cgroup *memcg) {}
    56	static inline void zswap_lruvec_state_init(struct lruvec *lruvec) {}
    57	static inline void zswap_page_swapin(struct page *page) {}
    58	#endif
    59
diff mbox series

Patch

diff --git a/include/linux/zswap.h b/include/linux/zswap.h
index 08c240e16a01..7cccc02cb9e9 100644
--- a/include/linux/zswap.h
+++ b/include/linux/zswap.h
@@ -30,7 +30,7 @@  struct zswap_lruvec_state {
 bool zswap_store(struct folio *folio);
 bool zswap_load(struct folio *folio);
 void zswap_invalidate(int type, pgoff_t offset);
-void zswap_swapon(int type);
+int zswap_swapon(int type);
 void zswap_swapoff(int type);
 void zswap_memcg_offline_cleanup(struct mem_cgroup *memcg);
 void zswap_lruvec_state_init(struct lruvec *lruvec);
@@ -50,7 +50,7 @@  static inline bool zswap_load(struct folio *folio)
 }
 
 static inline void zswap_invalidate(int type, pgoff_t offset) {}
-static inline void zswap_swapon(int type) {}
+static inline int zswap_swapon(int type) {}
 static inline void zswap_swapoff(int type) {}
 static inline void zswap_memcg_offline_cleanup(struct mem_cgroup *memcg) {}
 static inline void zswap_lruvec_state_init(struct lruvec *lruvec) {}
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 8be70912e298..939e7590feda 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2346,8 +2346,6 @@  static void enable_swap_info(struct swap_info_struct *p, int prio,
 				unsigned char *swap_map,
 				struct swap_cluster_info *cluster_info)
 {
-	zswap_swapon(p->type);
-
 	spin_lock(&swap_lock);
 	spin_lock(&p->lock);
 	setup_swap_info(p, prio, swap_map, cluster_info);
@@ -3165,6 +3163,10 @@  SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 	if (error)
 		goto bad_swap_unlock_inode;
 
+	error = zswap_swapon(p->type);
+	if (error)
+		goto free_swap_address_space;
+
 	/*
 	 * Flush any pending IO and dirty mappings before we start using this
 	 * swap device.
@@ -3173,7 +3175,7 @@  SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 	error = inode_drain_writes(inode);
 	if (error) {
 		inode->i_flags &= ~S_SWAPFILE;
-		goto free_swap_address_space;
+		goto free_swap_zswap;
 	}
 
 	mutex_lock(&swapon_mutex);
@@ -3197,6 +3199,8 @@  SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 
 	error = 0;
 	goto out;
+free_swap_zswap:
+	zswap_swapoff(p->type);
 free_swap_address_space:
 	exit_swap_address_space(p->type);
 bad_swap_unlock_inode:
diff --git a/mm/zswap.c b/mm/zswap.c
index 0f086ffd7b6a..5e2b8d5ee33b 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -1560,7 +1560,7 @@  bool zswap_store(struct folio *folio)
 	if (folio_test_large(folio))
 		return false;
 
-	if (!zswap_enabled || !tree)
+	if (!zswap_enabled)
 		return false;
 
 	/*
@@ -1850,19 +1850,20 @@  void zswap_invalidate(int type, pgoff_t offset)
 	spin_unlock(&tree->lock);
 }
 
-void zswap_swapon(int type)
+int zswap_swapon(int type)
 {
 	struct zswap_tree *tree;
 
 	tree = kzalloc(sizeof(*tree), GFP_KERNEL);
 	if (!tree) {
 		pr_err("alloc failed, zswap disabled for swap type %d\n", type);
-		return;
+		return -ENOMEM;
 	}
 
 	tree->rbroot = RB_ROOT;
 	spin_lock_init(&tree->lock);
 	zswap_trees[type] = tree;
+	return 0;
 }
 
 void zswap_swapoff(int type)