lkml.org 
[lkml]   [2003]   [May]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] per-cpu data in modules.
Date
Hi Andrew,

This uses the previous __alloc_percpu patch, to allow per-cpu
data within modules.

Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Name: per-cpu support inside modules
Author: Rusty Russell
Status: Tested on 2.5.69
Depends: Misc/kmalloc_percpu.patch.gz

D: This adds percpu support for modules.

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .12664-linux-2.5.69/include/linux/module.h .12664-linux-2.5.69.updated/include/linux/module.h
--- .12664-linux-2.5.69/include/linux/module.h 2003-05-05 12:37:12.000000000 +1000
+++ .12664-linux-2.5.69.updated/include/linux/module.h 2003-05-05 13:02:06.000000000 +1000
@@ -247,6 +247,9 @@ struct module
char *strtab;
#endif

+ /* Per-cpu data. */
+ void *percpu;
+
/* The command line arguments (may be mangled). People like
keeping pointers to this stuff */
char *args;
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .12664-linux-2.5.69/include/linux/percpu.h .12664-linux-2.5.69.updated/include/linux/percpu.h
--- .12664-linux-2.5.69/include/linux/percpu.h 2003-05-05 13:02:05.000000000 +1000
+++ .12664-linux-2.5.69.updated/include/linux/percpu.h 2003-05-05 13:02:41.000000000 +1000
@@ -31,10 +31,8 @@ extern void kfree_percpu(const void *);
extern unsigned long __per_cpu_offset[NR_CPUS];

/* Separate out the type, so (int[3], foo) works. */
-#ifndef MODULE
#define DEFINE_PER_CPU(type, name) \
__attribute__((__section__(".data.percpu"))) __typeof__(type) name##__per_cpu
-#endif

/* var is in discarded region: offset to particular copy we want */
#define per_cpu(var, cpu) (*RELOC_HIDE(&var##__per_cpu, __per_cpu_offset[cpu]))
@@ -43,11 +41,8 @@ extern unsigned long __per_cpu_offset[NR
extern void setup_per_cpu_areas(void);
#else /* !CONFIG_SMP */

-/* Can't define per-cpu variables in modules. Sorry --RR */
-#ifndef MODULE
#define DEFINE_PER_CPU(type, name) \
__typeof__(type) name##__per_cpu
-#endif

#define per_cpu(var, cpu) ((void)(cpu), var##__per_cpu)
#define __get_cpu_var(var) var##__per_cpu
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .12664-linux-2.5.69/kernel/module.c .12664-linux-2.5.69.updated/kernel/module.c
--- .12664-linux-2.5.69/kernel/module.c 2003-05-05 12:37:13.000000000 +1000
+++ .12664-linux-2.5.69.updated/kernel/module.c 2003-05-05 13:02:06.000000000 +1000
@@ -916,6 +916,8 @@ static void free_module(struct module *m
/* This may be NULL, but that's OK */
module_free(mod, mod->module_init);
kfree(mod->args);
+ if (mod->percpu)
+ kfree_percpu(mod->percpu);

/* Finally, free the core (containing the module structure) */
module_free(mod, mod->module_core);
@@ -942,10 +944,11 @@ static int simplify_symbols(Elf_Shdr *se
unsigned int symindex,
const char *strtab,
unsigned int versindex,
+ unsigned int pcpuindex,
struct module *mod)
{
Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
-
+ unsigned long secbase;
unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
int ret = 0;

@@ -982,10 +985,12 @@ static int simplify_symbols(Elf_Shdr *se
break;

default:
- sym[i].st_value
- = (unsigned long)
- (sechdrs[sym[i].st_shndx].sh_addr
- + sym[i].st_value);
+ /* Divert to percpu allocation if a percpu var. */
+ if (sym[i].st_shndx == pcpuindex)
+ secbase = (unsigned long)mod->percpu;
+ else
+ secbase = sechdrs[sym[i].st_shndx].sh_addr;
+ sym[i].st_value += secbase;
break;
}
}
@@ -1122,7 +1127,7 @@ static struct module *load_module(void _
char *secstrings, *args, *modmagic, *strtab = NULL;
unsigned int i, symindex = 0, strindex = 0, setupindex, exindex,
exportindex, modindex, obsparmindex, infoindex, gplindex,
- crcindex, gplcrcindex, versindex;
+ crcindex, gplcrcindex, versindex, pcpuindex;
long arglen;
struct module *mod;
long err = 0;
@@ -1197,6 +1202,7 @@ static struct module *load_module(void _
obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
+ pcpuindex = find_sec(hdr, sechdrs, secstrings, ".data.percpu");

/* Don't keep modinfo section */
sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
@@ -1275,6 +1281,17 @@ static struct module *load_module(void _
memset(ptr, 0, mod->init_size);
mod->module_init = ptr;

+ if (pcpuindex) {
+ /* We have a special allocation for this section. */
+ mod->percpu = __alloc_percpu(sechdrs[pcpuindex].sh_size,
+ sechdrs[pcpuindex].sh_addralign);
+ if (!mod->percpu) {
+ err = -ENOMEM;
+ goto free_init;
+ }
+ sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
+ }
+
/* Transfer each section which specifies SHF_ALLOC */
for (i = 0; i < hdr->e_shnum; i++) {
void *dest;
@@ -1304,7 +1321,8 @@ static struct module *load_module(void _
set_license(mod, get_modinfo(sechdrs, infoindex, "license"));

/* Fix up syms, so that st_value is a pointer to location. */
- err = simplify_symbols(sechdrs, symindex, strtab, versindex, mod);
+ err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
+ mod);
if (err < 0)
goto cleanup;

@@ -1343,6 +1361,15 @@ static struct module *load_module(void _
goto cleanup;
}

+ /* Finally, copy percpu area over. */
+ if (pcpuindex) {
+ for (i = 0; i < NR_CPUS; i++)
+ if (cpu_possible(i))
+ memcpy(per_cpu_ptr(mod->percpu, i),
+ (void *)sechdrs[pcpuindex].sh_addr,
+ sechdrs[pcpuindex].sh_size);
+ }
+
#ifdef CONFIG_KALLSYMS
mod->symtab = (void *)sechdrs[symindex].sh_addr;
mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
@@ -1381,6 +1408,9 @@ static struct module *load_module(void _

cleanup:
module_unload_free(mod);
+ if (mod->percpu)
+ kfree_percpu(mod->percpu);
+ free_init:
module_free(mod, mod->module_init);
free_core:
module_free(mod, mod->module_core);
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2005-03-22 13:35    [W:0.024 / U:0.040 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site