Eric Lee / smarc-ti-linux-kernel

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Commit bd77c04772da38fca510c81f78e51f727123b919

Authored by Eric Dumazet
Committed by Rusty Russell
1 parent 48fd11880b
Exists in master and in 20 other branches dlt-processor-sdk-linux-03.00.00.04, newt-ti-linux-3.12.y, processor-sdk-linux-01.00.00, processor-sdk-linux-02.00.01, smarc-ti-linux-3.12.10, smarc-ti-linux-3.12.y, smarc-ti-linux-3.14.y, smarc-ti-linux-3.15.y, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04, ti-linux-3.12.y, ti-linux-3.14.y, ti-linux-3.15.y, ti-lsk-linux-4.1.y

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>

Showing 3 changed files with 21 additions and 10 deletions Side-by-side Diff

include/linux/module.h
Diff comments   View file @ bd77c04
... ... @@ -205,6 +205,20 @@
205 205 MODULE_STATE_GOING,
206 206 };
207 207  
  208 +/**
  209 + * struct module_ref - per cpu module reference counts
  210 + * @incs: number of module get on this cpu
  211 + * @decs: number of module put on this cpu
  212 + *
  213 + * We force an alignment on 8 or 16 bytes, so that alloc_percpu()
  214 + * put @incs/@decs in same cache line, with no extra memory cost,
  215 + * since alloc_percpu() is fine grained.
  216 + */
  217 +struct module_ref {
  218 + unsigned long incs;
  219 + unsigned long decs;
  220 +} __attribute((aligned(2 * sizeof(unsigned long))));
  221 +
208 222 struct module
209 223 {
210 224 enum module_state state;
... ... @@ -347,10 +361,7 @@
347 361 /* Destruction function. */
348 362 void (*exit)(void);
349 363  
350   - struct module_ref {
351   - unsigned int incs;
352   - unsigned int decs;
353   - } __percpu *refptr;
  364 + struct module_ref __percpu *refptr;
354 365 #endif
355 366  
356 367 #ifdef CONFIG_CONSTRUCTORS
... ... @@ -434,7 +445,7 @@
434 445 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
435 446  
436 447 #ifdef CONFIG_MODULE_UNLOAD
437   -unsigned int module_refcount(struct module *mod);
  448 +unsigned long module_refcount(struct module *mod);
438 449 void __symbol_put(const char *symbol);
439 450 #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
440 451 void symbol_put_addr(void *addr);
kernel/debug/kdb/kdb_main.c
Diff comments   View file @ bd77c04
... ... @@ -1982,7 +1982,7 @@
1982 1982 kdb_printf("%-20s%8u 0x%p ", mod->name,
1983 1983 mod->core_size, (void *)mod);
1984 1984 #ifdef CONFIG_MODULE_UNLOAD
1985   - kdb_printf("%4d ", module_refcount(mod));
  1985 + kdb_printf("%4ld ", module_refcount(mod));
1986 1986 #endif
1987 1987 if (mod->state == MODULE_STATE_GOING)
1988 1988 kdb_printf(" (Unloading)");
... ... @@ -725,9 +725,9 @@
725 725 }
726 726 }
727 727  
728   -unsigned int module_refcount(struct module *mod)
  728 +unsigned long module_refcount(struct module *mod)
729 729 {
730   - unsigned int incs = 0, decs = 0;
  730 + unsigned long incs = 0, decs = 0;
731 731 int cpu;
732 732  
733 733 for_each_possible_cpu(cpu)
... ... @@ -853,7 +853,7 @@
853 853 struct module_use *use;
854 854 int printed_something = 0;
855 855  
856   - seq_printf(m, " %u ", module_refcount(mod));
  856 + seq_printf(m, " %lu ", module_refcount(mod));
857 857  
858 858 /* Always include a trailing , so userspace can differentiate
859 859 between this and the old multi-field proc format. */
... ... @@ -903,7 +903,7 @@
903 903 static ssize_t show_refcnt(struct module_attribute *mattr,
904 904 struct module_kobject *mk, char *buffer)
905 905 {
906   - return sprintf(buffer, "%u\n", module_refcount(mk->mod));
  906 + return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
907 907 }
908 908  
909 909 static struct module_attribute refcnt = {