From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754225AbcLICp1 (ORCPT ); Thu, 8 Dec 2016 21:45:27 -0500 Received: from mga04.intel.com ([192.55.52.120]:12084 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753798AbcLICpZ (ORCPT ); Thu, 8 Dec 2016 21:45:25 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,322,1477983600"; d="scan'208";a="1096719181" Subject: [PATCH v2 04/11] mm: cleanup sparse_init_one_section() return value From: Dan Williams To: akpm@linux-foundation.org Cc: toshi.kani@hpe.com, Mel Gorman , linux-kernel@vger.kernel.org, Stephen Bates , linux-mm@kvack.org, Johannes Weiner , Logan Gunthorpe , Vlastimil Babka Date: Thu, 08 Dec 2016 18:41:15 -0800 Message-ID: <148125127569.13512.1723769542125375411.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <148125125407.13512.1253904589564772668.stgit@dwillia2-desk3.amr.corp.intel.com> References: <148125125407.13512.1253904589564772668.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-9-g687f MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We mark and check that the section is present under a spin_lock() in sparse_add_one_section(), so the lock ensures it will not change between those 2 events. Also, we do not check the -EBUSY return value in sparse_init(). Just make sparse_init_one_section() return void and clean up the error handling. Cc: Andrew Morton Cc: Mel Gorman Cc: Vlastimil Babka Cc: Johannes Weiner Cc: Logan Gunthorpe Cc: Stephen Bates Signed-off-by: Dan Williams --- mm/sparse.c | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-) diff --git a/mm/sparse.c b/mm/sparse.c index 91e1908db23d..59966a3e8ff0 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -231,19 +231,14 @@ struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pn return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum); } -static int __meminit sparse_init_one_section(struct mem_section *ms, +static void __meminit sparse_init_one_section(struct mem_section *ms, unsigned long pnum, struct page *mem_map, struct mem_section_usage *usage) { - if (!present_section(ms)) - return -EINVAL; - ms->section_mem_map &= ~SECTION_MAP_MASK; ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) | SECTION_HAS_MEM_MAP; ms->usage = usage; - - return 1; } unsigned long usemap_size(void) @@ -690,11 +685,6 @@ static void free_map_bootmem(struct page *memmap) #endif /* CONFIG_MEMORY_HOTREMOVE */ #endif /* CONFIG_SPARSEMEM_VMEMMAP */ -/* - * returns the number of sections whose mem_maps were properly - * set. If this is <=0, then that means that the passed-in - * map was not consumed and must be freed. - */ int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn) { unsigned long section_nr = pfn_to_section_nr(start_pfn); @@ -725,7 +715,7 @@ int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn) ms = __pfn_to_section(start_pfn); if (ms->section_mem_map & SECTION_MARKED_PRESENT) { - ret = -EEXIST; + ret = -EBUSY; goto out; } @@ -733,15 +723,16 @@ int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn) ms->section_mem_map |= SECTION_MARKED_PRESENT; - ret = sparse_init_one_section(ms, section_nr, memmap, usage); + sparse_init_one_section(ms, section_nr, memmap, usage); out: pgdat_resize_unlock(pgdat, &flags); - if (ret <= 0) { + if (ret < 0 && ret != -EEXIST) { kfree(usage); __kfree_section_memmap(memmap); + return ret; } - return ret; + return 0; } #ifdef CONFIG_MEMORY_HOTREMOVE