Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933235AbdGXXJi (ORCPT ); Mon, 24 Jul 2017 19:09:38 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:59868 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756837AbdGXXCn (ORCPT ); Mon, 24 Jul 2017 19:02:43 -0400 From: Dennis Zhou To: Tejun Heo , Christoph Lameter , Josef Bacik CC: , , , Dennis Zhou Subject: [PATCH v2 06/23] percpu: end chunk area maps page aligned for the populated bitmap Date: Mon, 24 Jul 2017 19:02:03 -0400 Message-ID: <20170724230220.21774-7-dennisz@fb.com> X-Mailer: git-send-email 2.13.3 In-Reply-To: <20170724230220.21774-1-dennisz@fb.com> References: <20170724230220.21774-1-dennisz@fb.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [192.168.52.123] X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-07-24_14:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3182 Lines: 93 From: "Dennis Zhou (Facebook)" The area map allocator manages the first chunk area by hiding all but the region it is responsible for serving in the area map. To align this with the populated page bitmap, end_offset is introduced to keep track of the delta to end page aligned. The area map is appended with the page aligned end when necessary to be in line with how the bitmap allocator requires the ending to be aligned with the LCM of PAGE_SIZE and the size of each bitmap block. percpu_stats is updated to ignore this region when present. Signed-off-by: Dennis Zhou --- mm/percpu-internal.h | 3 +++ mm/percpu-stats.c | 5 +++-- mm/percpu.c | 9 +++++++++ 3 files changed, 15 insertions(+), 2 deletions(-) diff --git a/mm/percpu-internal.h b/mm/percpu-internal.h index c876b5b..f02f31c 100644 --- a/mm/percpu-internal.h +++ b/mm/percpu-internal.h @@ -26,6 +26,9 @@ struct pcpu_chunk { int start_offset; /* the overlap with the previous region to have a page aligned base_addr */ + int end_offset; /* additional area required to + have the region end page + aligned */ int nr_populated; /* # of populated pages */ unsigned long populated[]; /* populated bitmap */ }; diff --git a/mm/percpu-stats.c b/mm/percpu-stats.c index 32f3550..ffbdb96 100644 --- a/mm/percpu-stats.c +++ b/mm/percpu-stats.c @@ -51,7 +51,7 @@ static int find_max_map_used(void) static void chunk_map_stats(struct seq_file *m, struct pcpu_chunk *chunk, int *buffer) { - int i, s_index, last_alloc, alloc_sign, as_len; + int i, s_index, e_index, last_alloc, alloc_sign, as_len; int *alloc_sizes, *p; /* statistics */ int sum_frag = 0, max_frag = 0; @@ -59,10 +59,11 @@ static void chunk_map_stats(struct seq_file *m, struct pcpu_chunk *chunk, alloc_sizes = buffer; s_index = (chunk->start_offset) ? 1 : 0; + e_index = chunk->map_used - ((chunk->end_offset) ? 1 : 0); /* find last allocation */ last_alloc = -1; - for (i = chunk->map_used - 1; i >= s_index; i--) { + for (i = e_index - 1; i >= s_index; i--) { if (chunk->map[i] & 1) { last_alloc = i; break; diff --git a/mm/percpu.c b/mm/percpu.c index 2e785a7..1d2c980 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -715,12 +715,16 @@ static struct pcpu_chunk * __init pcpu_alloc_first_chunk(void *base_addr, int init_map_size) { struct pcpu_chunk *chunk; + int region_size; + + region_size = PFN_ALIGN(start_offset + map_size); chunk = memblock_virt_alloc(pcpu_chunk_struct_size, 0); INIT_LIST_HEAD(&chunk->list); INIT_LIST_HEAD(&chunk->map_extend_list); chunk->base_addr = base_addr; chunk->start_offset = start_offset; + chunk->end_offset = region_size - chunk->start_offset - map_size; chunk->map = map; chunk->map_alloc = init_map_size; @@ -735,6 +739,11 @@ static struct pcpu_chunk * __init pcpu_alloc_first_chunk(void *base_addr, chunk->map[2] = (chunk->start_offset + chunk->free_size) | 1; chunk->map_used = 2; + if (chunk->end_offset) { + /* hide the end of the bitmap */ + chunk->map[++chunk->map_used] = region_size | 1; + } + return chunk; } -- 2.9.3