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(-)
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)
--
b4 0.10.1Hi 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
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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!
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