From dca496451bddea9aa87b7510dc2eb413d1a19dfd Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 2 Sep 2014 14:46:01 -0400 Subject: percpu: move common parts out of pcpu_[de]populate_chunk() percpu-vm and percpu-km implement separate versions of pcpu_[de]populate_chunk() and some part which is or should be common are currently in the specific implementations. Make the following changes. * Allocate area clearing is moved from the pcpu_populate_chunk() implementations to pcpu_alloc(). This makes percpu-km's version noop. * Quick exit tests in pcpu_[de]populate_chunk() of percpu-vm are moved to their respective callers so that they are applied to percpu-km too. This doesn't make any meaningful difference as both functions are noop for percpu-km; however, this is more consistent and will help implementing atomic allocation support. Signed-off-by: Tejun Heo --- mm/percpu-km.c | 5 ----- mm/percpu-vm.c | 27 +-------------------------- mm/percpu.c | 39 ++++++++++++++++++++++++++++++--------- 3 files changed, 31 insertions(+), 40 deletions(-) (limited to 'mm') diff --git a/mm/percpu-km.c b/mm/percpu-km.c index 89633fefc6a2..9a9096f08867 100644 --- a/mm/percpu-km.c +++ b/mm/percpu-km.c @@ -35,11 +35,6 @@ static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size) { - unsigned int cpu; - - for_each_possible_cpu(cpu) - memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size); - return 0; } diff --git a/mm/percpu-vm.c b/mm/percpu-vm.c index d9e0b615492e..edf709793318 100644 --- a/mm/percpu-vm.c +++ b/mm/percpu-vm.c @@ -265,7 +265,7 @@ static void pcpu_post_map_flush(struct pcpu_chunk *chunk, * @size: size of the area to populate in bytes * * For each cpu, populate and map pages [@page_start,@page_end) into - * @chunk. The area is cleared on return. + * @chunk. * * CONTEXT: * pcpu_alloc_mutex, does GFP_KERNEL allocation. @@ -276,18 +276,8 @@ static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size) int page_end = PFN_UP(off + size); int free_end = page_start, unmap_end = page_start; struct page **pages; - unsigned int cpu; int rs, re, rc; - /* quick path, check whether all pages are already there */ - rs = page_start; - pcpu_next_pop(chunk, &rs, &re, page_end); - if (rs == page_start && re == page_end) - goto clear; - - /* need to allocate and map pages, this chunk can't be immutable */ - WARN_ON(chunk->immutable); - pages = pcpu_get_pages(chunk); if (!pages) return -ENOMEM; @@ -308,10 +298,6 @@ static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size) } pcpu_post_map_flush(chunk, page_start, page_end); - bitmap_set(chunk->populated, page_start, page_end - page_start); -clear: - for_each_possible_cpu(cpu) - memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size); return 0; err_unmap: @@ -345,15 +331,6 @@ static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size) struct page **pages; int rs, re; - /* quick path, check whether it's empty already */ - rs = page_start; - pcpu_next_unpop(chunk, &rs, &re, page_end); - if (rs == page_start && re == page_end) - return; - - /* immutable chunks can't be depopulated */ - WARN_ON(chunk->immutable); - /* * If control reaches here, there must have been at least one * successful population attempt so the temp pages array must @@ -372,8 +349,6 @@ static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size) pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end) pcpu_free_pages(chunk, pages, rs, re); - - bitmap_clear(chunk->populated, page_start, page_end - page_start); } static struct pcpu_chunk *pcpu_create_chunk(void) diff --git a/mm/percpu.c b/mm/percpu.c index da997f9800bd..6087384f6ef0 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -709,7 +709,8 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved) static int warn_limit = 10; struct pcpu_chunk *chunk; const char *err; - int slot, off, new_alloc; + int slot, off, new_alloc, cpu; + int page_start, page_end, rs, re; unsigned long flags; void __percpu *ptr; @@ -802,17 +803,32 @@ restart: area_found: spin_unlock_irqrestore(&pcpu_lock, flags); - /* populate, map and clear the area */ - if (pcpu_populate_chunk(chunk, off, size)) { - spin_lock_irqsave(&pcpu_lock, flags); - pcpu_free_area(chunk, off); - err = "failed to populate"; - goto fail_unlock; + /* populate if not all pages are already there */ + page_start = PFN_DOWN(off); + page_end = PFN_UP(off + size); + + rs = page_start; + pcpu_next_pop(chunk, &rs, &re, page_end); + + if (rs != page_start || re != page_end) { + WARN_ON(chunk->immutable); + + if (pcpu_populate_chunk(chunk, off, size)) { + spin_lock_irqsave(&pcpu_lock, flags); + pcpu_free_area(chunk, off); + err = "failed to populate"; + goto fail_unlock; + } + + bitmap_set(chunk->populated, page_start, page_end - page_start); } mutex_unlock(&pcpu_alloc_mutex); - /* return address relative to base address */ + /* clear the areas and return address relative to base address */ + for_each_possible_cpu(cpu) + memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size); + ptr = __addr_to_pcpu_ptr(chunk->base_addr + off); kmemleak_alloc_percpu(ptr, size); return ptr; @@ -903,7 +919,12 @@ static void pcpu_reclaim(struct work_struct *work) spin_unlock_irq(&pcpu_lock); list_for_each_entry_safe(chunk, next, &todo, list) { - pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size); + int rs = 0, re; + + pcpu_next_unpop(chunk, &rs, &re, PFN_UP(pcpu_unit_size)); + if (rs || re != PFN_UP(pcpu_unit_size)) + pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size); + pcpu_destroy_chunk(chunk); } -- cgit