diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2012-01-13 09:32:14 +1030 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2012-01-13 09:32:14 +1030 |
| commit | bd77c04772da38fca510c81f78e51f727123b919 (patch) | |
| tree | 8554b40191d3d5adebbd2461d26450c0ed7295d4 | |
| parent | 48fd11880b5ef04270be8a87d9a9a9ee2fdae338 (diff) | |
module: struct module_ref should contains long fields
module_ref contains two "unsigned int" fields.
Thats now too small, since some machines can open more than 2^32 files.
Check commit 518de9b39e8 (fs: allow for more than 2^31 files) for
reference.
We can add an aligned(2 * sizeof(unsigned long)) attribute to force
alloc_percpu() allocating module_ref areas in single cache lines.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Rusty Russell <rusty@rustcorp.com.au>
CC: Tejun Heo <tj@kernel.org>
CC: Robin Holt <holt@sgi.com>
CC: David Miller <davem@davemloft.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| -rw-r--r-- | include/linux/module.h | 21 | ||||
| -rw-r--r-- | kernel/debug/kdb/kdb_main.c | 2 | ||||
| -rw-r--r-- | kernel/module.c | 8 |
3 files changed, 21 insertions, 10 deletions
diff --git a/include/linux/module.h b/include/linux/module.h index 3cb7839a60b..4598bf03e98 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -205,6 +205,20 @@ enum module_state MODULE_STATE_GOING, }; +/** + * struct module_ref - per cpu module reference counts + * @incs: number of module get on this cpu + * @decs: number of module put on this cpu + * + * We force an alignment on 8 or 16 bytes, so that alloc_percpu() + * put @incs/@decs in same cache line, with no extra memory cost, + * since alloc_percpu() is fine grained. + */ +struct module_ref { + unsigned long incs; + unsigned long decs; +} __attribute((aligned(2 * sizeof(unsigned long)))); + struct module { enum module_state state; @@ -347,10 +361,7 @@ struct module /* Destruction function. */ void (*exit)(void); - struct module_ref { - unsigned int incs; - unsigned int decs; - } __percpu *refptr; + struct module_ref __percpu *refptr; #endif #ifdef CONFIG_CONSTRUCTORS @@ -434,7 +445,7 @@ extern void __module_put_and_exit(struct module *mod, long code) #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code); #ifdef CONFIG_MODULE_UNLOAD -unsigned int module_refcount(struct module *mod); +unsigned long module_refcount(struct module *mod); void __symbol_put(const char *symbol); #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x) void symbol_put_addr(void *addr); diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index 63786e71a3c..e2ae7349437 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -1982,7 +1982,7 @@ static int kdb_lsmod(int argc, const char **argv) kdb_printf("%-20s%8u 0x%p ", mod->name, mod->core_size, (void *)mod); #ifdef CONFIG_MODULE_UNLOAD - kdb_printf("%4d ", module_refcount(mod)); + kdb_printf("%4ld ", module_refcount(mod)); #endif if (mod->state == MODULE_STATE_GOING) kdb_printf(" (Unloading)"); diff --git a/kernel/module.c b/kernel/module.c index 4928cffc3dc..14b8e82e05d 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -725,9 +725,9 @@ static int try_stop_module(struct module *mod, int flags, int *forced) } } -unsigned int module_refcount(struct module *mod) +unsigned long module_refcount(struct module *mod) { - unsigned int incs = 0, decs = 0; + unsigned long incs = 0, decs = 0; int cpu; for_each_possible_cpu(cpu) @@ -853,7 +853,7 @@ static inline void print_unload_info(struct seq_file *m, struct module *mod) struct module_use *use; int printed_something = 0; - seq_printf(m, " %u ", module_refcount(mod)); + seq_printf(m, " %lu ", module_refcount(mod)); /* Always include a trailing , so userspace can differentiate between this and the old multi-field proc format. */ @@ -903,7 +903,7 @@ EXPORT_SYMBOL_GPL(symbol_put_addr); static ssize_t show_refcnt(struct module_attribute *mattr, struct module_kobject *mk, char *buffer) { - return sprintf(buffer, "%u\n", module_refcount(mk->mod)); + return sprintf(buffer, "%lu\n", module_refcount(mk->mod)); } static struct module_attribute refcnt = { |