diff options
| author | Rusty Russell <rusty@rustcorp.com.au> | 2005-08-10 13:52:38 +0100 |
|---|---|---|
| committer | Chris Wright <chrisw@osdl.org> | 2005-08-14 17:20:11 -0700 |
| commit | 24eda4e69d4f0a4d5a66c8b5a8fa9b895d832368 (patch) | |
| tree | d0396ba53a81783db3ba6ae6f29349504cf66809 | |
| parent | a3692f99ef19cfb7fe0420837852108450dd8124 (diff) | |
[PATCH] Module per-cpu alignment cannot always be met
Fwd from Daniel Drake <dsd@gentoo.org>.
The module code assumes noone will ever ask for a per-cpu area more than
SMP_CACHE_BYTES aligned. However, as these cases show, gcc asks sometimes
asks for 32-byte alignment for the per-cpu section on a module, and if
CONFIG_X86_L1_CACHE_SHIFT is 4, we hit that BUG_ON(). This is obviously an
unusual combination, as there have been few reports, but better to warn
than die.
See:
http://www.ussg.iu.edu/hypermail/linux/kernel/0409.0/0768.html
And more recently:
http://bugs.gentoo.org/show_bug.cgi?id=97006
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | kernel/module.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/kernel/module.c b/kernel/module.c index 83b3d376708..71ff04191d4 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -249,13 +249,18 @@ static inline unsigned int block_size(int val) /* Created by linker magic */ extern char __per_cpu_start[], __per_cpu_end[]; -static void *percpu_modalloc(unsigned long size, unsigned long align) +static void *percpu_modalloc(unsigned long size, unsigned long align, + const char *name) { unsigned long extra; unsigned int i; void *ptr; - BUG_ON(align > SMP_CACHE_BYTES); + if (align > SMP_CACHE_BYTES) { + printk(KERN_WARNING "%s: per-cpu alignment %li > %i\n", + name, align, SMP_CACHE_BYTES); + align = SMP_CACHE_BYTES; + } ptr = __per_cpu_start; for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) { @@ -347,7 +352,8 @@ static int percpu_modinit(void) } __initcall(percpu_modinit); #else /* ... !CONFIG_SMP */ -static inline void *percpu_modalloc(unsigned long size, unsigned long align) +static inline void *percpu_modalloc(unsigned long size, unsigned long align, + const char *name) { return NULL; } @@ -1554,7 +1560,8 @@ static struct module *load_module(void __user *umod, if (pcpuindex) { /* We have a special allocation for this section. */ percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size, - sechdrs[pcpuindex].sh_addralign); + sechdrs[pcpuindex].sh_addralign, + mod->name); if (!percpu) { err = -ENOMEM; goto free_mod; |