diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index e87bdbfbcc75..844e9a654d0b 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -497,6 +497,13 @@ and is between 256 and 4096 characters. It is defined in the file Also note the kernel might malfunction if you disable some critical bits. + cmo_free_hint= [PPC] Format: { yes | no } + Specify whether pages are marked as being inactive + when they are freed. This is used in CMO environments + to determine OS memory pressure for page stealing by + a hypervisor. + Default: yes + code_bytes [X86] How many bytes of object code to print in an oops report. Range: 0 - 8192 diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h index 32cbf16f10ea..4940662ee87e 100644 --- a/arch/powerpc/include/asm/page.h +++ b/arch/powerpc/include/asm/page.h @@ -231,6 +231,11 @@ extern void copy_user_page(void *to, void *from, unsigned long vaddr, struct page *p); extern int page_is_ram(unsigned long pfn); +#ifdef CONFIG_PPC_SMLPAR +void arch_free_page(struct page *page, int order); +#define HAVE_ARCH_FREE_PAGE +#endif + struct vm_area_struct; typedef struct page *pgtable_t; diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c index 52a80e5840e8..e3139fa5e556 100644 --- a/arch/powerpc/platforms/pseries/lpar.c +++ b/arch/powerpc/platforms/pseries/lpar.c @@ -609,3 +609,55 @@ void __init hpte_init_lpar(void) ppc_md.flush_hash_range = pSeries_lpar_flush_hash_range; ppc_md.hpte_clear_all = pSeries_lpar_hptab_clear; } + +#ifdef CONFIG_PPC_SMLPAR +#define CMO_FREE_HINT_DEFAULT 1 +static int cmo_free_hint_flag = CMO_FREE_HINT_DEFAULT; + +static int __init cmo_free_hint(char *str) +{ + char *parm; + parm = strstrip(str); + + if (strcasecmp(parm, "no") == 0 || strcasecmp(parm, "off") == 0) { + printk(KERN_INFO "cmo_free_hint: CMO free page hinting is not active.\n"); + cmo_free_hint_flag = 0; + return 1; + } + + cmo_free_hint_flag = 1; + printk(KERN_INFO "cmo_free_hint: CMO free page hinting is active.\n"); + + if (strcasecmp(parm, "yes") == 0 || strcasecmp(parm, "on") == 0) + return 1; + + return 0; +} + +__setup("cmo_free_hint=", cmo_free_hint); + +static void pSeries_set_page_state(struct page *page, int order, + unsigned long state) +{ + int i, j; + unsigned long cmo_page_sz, addr; + + cmo_page_sz = cmo_get_page_size(); + addr = __pa((unsigned long)page_address(page)); + + for (i = 0; i < (1 << order); i++, addr += PAGE_SIZE) { + for (j = 0; j < PAGE_SIZE; j += cmo_page_sz) + plpar_hcall_norets(H_PAGE_INIT, state, addr + j, 0); + } +} + +void arch_free_page(struct page *page, int order) +{ + if (!cmo_free_hint_flag || !firmware_has_feature(FW_FEATURE_CMO)) + return; + + pSeries_set_page_state(page, order, H_PAGE_SET_UNUSED); +} +EXPORT_SYMBOL(arch_free_page); + +#endif