diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 11 | ||||
| -rw-r--r-- | arch/x86/kernel/setup_percpu.c | 24 | ||||
| -rw-r--r-- | include/linux/percpu.h | 12 | ||||
| -rw-r--r-- | mm/percpu.c | 32 |
4 files changed, 56 insertions, 23 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 12e9eb77ee0d..dee9ce2e6cfa 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1919,11 +1919,12 @@ and is between 256 and 4096 characters. It is defined in the file Format: { 0 | 1 } See arch/parisc/kernel/pdc_chassis.c - percpu_alloc= [X86] Select which percpu first chunk allocator to use. - Allowed values are one of "lpage", "embed" and "page". - See comments in arch/x86/kernel/setup_percpu.c for - details on each allocator. This parameter is primarily - for debugging and performance comparison. + percpu_alloc= Select which percpu first chunk allocator to use. + Currently supported values are "embed", "page" and + "lpage". Archs may support subset or none of the + selections. See comments in mm/percpu.c for details + on each allocator. This parameter is primarily for + debugging and performance comparison. pf. [PARIDE] See Documentation/blockdev/paride.txt. diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c index 1e17711c29d6..b961d99e6416 100644 --- a/arch/x86/kernel/setup_percpu.c +++ b/arch/x86/kernel/setup_percpu.c @@ -267,16 +267,6 @@ static ssize_t __init setup_pcpu_page(size_t static_size) pcpup_populate_pte); } -/* for explicit first chunk allocator selection */ -static char pcpu_chosen_alloc[16] __initdata; - -static int __init percpu_alloc_setup(char *str) -{ - strncpy(pcpu_chosen_alloc, str, sizeof(pcpu_chosen_alloc) - 1); - return 0; -} -early_param("percpu_alloc", percpu_alloc_setup); - static inline void setup_percpu_segment(int cpu) { #ifdef CONFIG_X86_32 @@ -307,19 +297,17 @@ void __init setup_per_cpu_areas(void) * each allocator for details. */ ret = -EINVAL; - if (strlen(pcpu_chosen_alloc)) { - if (strcmp(pcpu_chosen_alloc, "page")) { - if (!strcmp(pcpu_chosen_alloc, "lpage")) + if (pcpu_chosen_fc != PCPU_FC_AUTO) { + if (pcpu_chosen_fc != PCPU_FC_PAGE) { + if (pcpu_chosen_fc == PCPU_FC_LPAGE) ret = setup_pcpu_lpage(static_size, true); - else if (!strcmp(pcpu_chosen_alloc, "embed")) - ret = setup_pcpu_embed(static_size, true); else - pr_warning("PERCPU: unknown allocator %s " - "specified\n", pcpu_chosen_alloc); + ret = setup_pcpu_embed(static_size, true); + if (ret < 0) pr_warning("PERCPU: %s allocator failed (%zd), " "falling back to page size\n", - pcpu_chosen_alloc, ret); + pcpu_fc_names[pcpu_chosen_fc], ret); } } else { ret = setup_pcpu_lpage(static_size, false); diff --git a/include/linux/percpu.h b/include/linux/percpu.h index e26788e0da4a..9be05cbe5ee0 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -59,6 +59,18 @@ extern void *pcpu_base_addr; extern const int *pcpu_unit_map; +enum pcpu_fc { + PCPU_FC_AUTO, + PCPU_FC_EMBED, + PCPU_FC_PAGE, + PCPU_FC_LPAGE, + + PCPU_FC_NR, +}; +extern const char *pcpu_fc_names[PCPU_FC_NR]; + +extern enum pcpu_fc pcpu_chosen_fc; + typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size); typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size); typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr); diff --git a/mm/percpu.c b/mm/percpu.c index 7971997de310..7fb40bb1555a 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -1414,6 +1414,38 @@ size_t __init pcpu_setup_first_chunk(size_t static_size, size_t reserved_size, return pcpu_unit_size; } +const char *pcpu_fc_names[PCPU_FC_NR] __initdata = { + [PCPU_FC_AUTO] = "auto", + [PCPU_FC_EMBED] = "embed", + [PCPU_FC_PAGE] = "page", + [PCPU_FC_LPAGE] = "lpage", +}; + +enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO; + +static int __init percpu_alloc_setup(char *str) +{ + if (0) + /* nada */; +#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK + else if (!strcmp(str, "embed")) + pcpu_chosen_fc = PCPU_FC_EMBED; +#endif +#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK + else if (!strcmp(str, "page")) + pcpu_chosen_fc = PCPU_FC_PAGE; +#endif +#ifdef CONFIG_NEED_PER_CPU_LPAGE_FIRST_CHUNK + else if (!strcmp(str, "lpage")) + pcpu_chosen_fc = PCPU_FC_LPAGE; +#endif + else + pr_warning("PERCPU: unknown allocator %s specified\n", str); + + return 0; +} +early_param("percpu_alloc", percpu_alloc_setup); + static inline size_t pcpu_calc_fc_sizes(size_t static_size, size_t reserved_size, ssize_t *dyn_sizep) |