Messages in this thread | | | Date | Tue, 30 Nov 2021 14:42:18 +0800 | Subject | Re: [PATCH RFC 4/4] mm: percpu: Add generic pcpu_populate_pte() function | From | Kefeng Wang <> |
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On 2021/11/30 6:49, Dennis Zhou wrote: > On Sun, Nov 21, 2021 at 05:35:57PM +0800, Kefeng Wang wrote: >> When NEED_PER_CPU_PAGE_FIRST_CHUNK enabled, we need a function to >> populate pte, add a generic pcpu populate pte function and switch >> to use it. >> >> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> >> --- >> arch/powerpc/kernel/setup_64.c | 47 +-------------------- >> arch/sparc/kernel/smp_64.c | 57 +------------------------ >> arch/x86/kernel/setup_percpu.c | 5 +-- >> drivers/base/arch_numa.c | 51 +--------------------- >> include/linux/percpu.h | 5 +-- >> mm/percpu.c | 77 +++++++++++++++++++++++++++++++--- >> 6 files changed, 79 insertions(+), 163 deletions(-) >> ... >> diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c >> index cd672bd46241..4eadbe45078e 100644 >> --- a/arch/x86/kernel/setup_percpu.c >> +++ b/arch/x86/kernel/setup_percpu.c >> @@ -101,7 +101,7 @@ static int __init pcpu_cpu_to_node(int cpu) >> return IS_ENABLED(CONFIG_NUMA) ? early_cpu_to_node(cpu) : NUMA_NO_NODE; >> } >> >> -static void __init pcpup_populate_pte(unsigned long addr) >> +void __init pcpu_populate_pte(unsigned long addr) >> { >> populate_extra_pte(addr); >> } >> @@ -163,8 +163,7 @@ void __init setup_per_cpu_areas(void) >> } >> if (rc < 0) >> rc = pcpu_page_first_chunk(PERCPU_FIRST_CHUNK_RESERVE, >> - pcpu_cpu_to_node, >> - pcpup_populate_pte); >> + pcpu_cpu_to_node); > x86 has it's own implementation that differs for 32 bit. I'm not > confident this is correct to drop in as a replacement for x86, so I'd > prefer to keep populate_pte_fn() around.
The x86's pcpup_populate_pte() version is not dropped.
We define a __weak pcpu_populate_pte function in mm/percpu.c,
and there is a own version on x86, so no function change on x86.
I will add this into changelog,
arch/x86/kernel/setup_percpu.c: void __init pcpu_populate_pte(unsigned long addr) include/linux/percpu.h: void __init pcpu_populate_pte(unsigned long addr); mm/percpu.c: void __init __weak pcpu_populate_pte(unsigned long addr) mm/percpu.c: pcpu_populate_pte(unit_addr + (i << PAGE_SHIFT));
>> diff --git a/include/linux/percpu.h b/include/linux/percpu.h >> index d73c97ef4ff4..f1ec5ad1351c 100644 >> --- a/include/linux/percpu.h >> +++ b/include/linux/percpu.h >> @@ -95,7 +95,6 @@ extern const char * const pcpu_fc_names[PCPU_FC_NR]; >> extern enum pcpu_fc pcpu_chosen_fc; >> >> typedef int (pcpu_fc_cpu_to_node_fn_t)(int cpu); >> -typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr); >> typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to); >> >> extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, >> @@ -113,9 +112,9 @@ extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, >> #endif >> >> #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK >> +void __init pcpu_populate_pte(unsigned long addr); >> extern int __init pcpu_page_first_chunk(size_t reserved_size, >> - pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn, >> - pcpu_fc_populate_pte_fn_t populate_pte_fn); >> + pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn); >> #endif >> >> extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align) __alloc_size(1); >> diff --git a/mm/percpu.c b/mm/percpu.c >> index efaa1cbaf73d..d907daed04eb 100644 >> --- a/mm/percpu.c >> +++ b/mm/percpu.c >> @@ -3162,11 +3162,80 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, >> #endif /* BUILD_EMBED_FIRST_CHUNK */ >> ... >> +void __init __weak pcpu_populate_pte(unsigned long addr) >> +{ >> + pgd_t *pgd = pgd_offset_k(addr); >> + p4d_t *p4d; >> + pud_t *pud; >> + pmd_t *pmd; >> + >> + if (pgd_none(*pgd)) { >> + p4d_t *new; >> + >> + new = memblock_alloc_from(P4D_TABLE_SIZE, P4D_TABLE_SIZE, PAGE_SIZE); > It's unnecessary to specify a min_addr to memblock_alloc_from() as it > won't allocate 0 anyway. So please use memblock_alloc() instead.
ok, will use memblock_alloc in this function
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