The exciting thing here is the getting rid of stop_machine on module

removal.  This is possible by using a simple atomic_t for the counter,
 rather than our fancy per-cpu counter: it turns out that no one is doing
 a module increment per net packet, so the slowdown should be in the noise.
 
 Also, script fixed for new git version.
 
 Cheers,
 Rusty.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJUk3cQAAoJENkgDmzRrbjxr44P/25ZBYmKZZ3XM3flt2o0LCti
 1Px+MRbWuXhueWQOYZSXOO3c2ENNuV3siaU4jQZqnxslpdvT4rVsVFkYuwva2vHT
 hqpoq1Hz++yjFJArjERFOdoZ1gxkBbZQQGYm8esToAqU3b2Z74SrU48dPwp65q/1
 r6hbXdWSiKALEBZeW2coi+QVCL/oxE8hmNqDO1mpe82aEKu0xIVpTdU5vAfBIj8/
 Z95U2bx+CjiP7khhSjBGtltLqxL6QXw1m2eg1gO9nf1gJNI0/dAY6IJmFbGz+7Bt
 CAyc9BRsB40Em8G7d7wr4FsURcLfmYNdjtx79j+Rot5PkVIi+Ztv7C1QYlMQESPa
 ESddUMySOmKlzTm50w3ZLvV1ZTRU8TjmttSkzQYZ3csCLkKUgfeL9SAxU9KGoA2l
 jFxrvDcWEHtuU1D/FeYyOofNaD/BflPfdhj4WAm9XnPPi+THEu7fulWJaIP4glHh
 8TpYNbinXuZqXO4nJ41Ad5utbSbBQa4fFBUuViWRTU0TtWJT2HVqn/XoYJ5mnPEz
 IbYh31rQDKFJKzePfscWrJ6XzoF59yGiAVcWcI3HS7aT8bFZGapAQu9mNCVu+cLF
 uRxWrukHG7d8YeYrAtbVXWfxArR155V9QJN55hQ1nKLq2M03gNvYTtAPw2yEsfuw
 u3Fk/KkV1RfaiFurjoG/
 =rDum
 -----END PGP SIGNATURE-----

Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull module updates from Rusty Russell:
 "The exciting thing here is the getting rid of stop_machine on module
  removal.  This is possible by using a simple atomic_t for the counter,
  rather than our fancy per-cpu counter: it turns out that no one is
  doing a module increment per net packet, so the slowdown should be in
  the noise"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  param: do not set store func without write perm
  params: cleanup sysfs allocation
  kernel:module Fix coding style errors and warnings.
  module: Remove stop_machine from module unloading
  module: Replace module_ref with atomic_t refcnt
  lib/bug: Use RCU list ops for module_bug_list
  module: Unlink module with RCU synchronizing instead of stop_machine
  module: Wait for RCU synchronizing before releasing a module
This commit is contained in:
Linus Torvalds 2014-12-18 20:55:41 -08:00
commit d790be3863
5 changed files with 137 additions and 168 deletions

View file

@ -210,20 +210,6 @@ enum module_state {
MODULE_STATE_UNFORMED, /* Still setting it up. */
};
/**
* 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;
@ -367,7 +353,7 @@ struct module {
/* Destruction function. */
void (*exit)(void);
struct module_ref __percpu *refptr;
atomic_t refcnt;
#endif
#ifdef CONFIG_CONSTRUCTORS