From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx128.postini.com [74.125.245.128]) by kanga.kvack.org (Postfix) with SMTP id 0C4A76B0032 for ; Tue, 3 Sep 2013 20:25:57 -0400 (EDT) Message-ID: <1378254257.10300.921.camel@misato.fc.hp.com> Subject: Re: [PATCH 06/11] memblock: Improve memblock to support allocation from lower address. From: Toshi Kani Date: Tue, 03 Sep 2013 18:24:17 -0600 In-Reply-To: <1377596268-31552-7-git-send-email-tangchen@cn.fujitsu.com> References: <1377596268-31552-1-git-send-email-tangchen@cn.fujitsu.com> <1377596268-31552-7-git-send-email-tangchen@cn.fujitsu.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Tang Chen Cc: rjw@sisk.pl, lenb@kernel.org, tglx@linutronix.de, mingo@elte.hu, hpa@zytor.com, akpm@linux-foundation.org, tj@kernel.org, trenn@suse.de, yinghai@kernel.org, jiang.liu@huawei.com, wency@cn.fujitsu.com, laijs@cn.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, izumi.taku@jp.fujitsu.com, mgorman@suse.de, minchan@kernel.org, mina86@mina86.com, gong.chen@linux.intel.com, vasilis.liaskovitis@profitbricks.com, lwoodman@redhat.com, riel@redhat.com, jweiner@redhat.com, prarit@redhat.com, zhangyanfei@cn.fujitsu.com, x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-acpi@vger.kernel.org On Tue, 2013-08-27 at 17:37 +0800, Tang Chen wrote: > This patch modifies the memblock_find_in_range_node() to support two > different allocation orders. After this patch, memblock will check > memblock.current_order, and decide in which order to allocate memory. > > Signed-off-by: Tang Chen > Reviewed-by: Zhang Yanfei > --- > mm/memblock.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++--------- > 1 files changed, 75 insertions(+), 15 deletions(-) > > diff --git a/mm/memblock.c b/mm/memblock.c > index 8f1e2d4..961d4a5 100644 > --- a/mm/memblock.c > +++ b/mm/memblock.c > @@ -85,6 +85,77 @@ static long __init_memblock memblock_overlaps_region(struct memblock_type *type, > } > > /** > + * __memblock_find_range - find free area utility > + * @start: start of candidate range, can be %MEMBLOCK_ALLOC_ACCESSIBLE > + * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE} > + * @size: size of free area to find > + * @align: alignment of free area to find > + * @nid: nid of the free area to find, %MAX_NUMNODES for any node > + * > + * Utility called from memblock_find_in_range_node(), find free area from > + * lower address to higher address. > + * > + * RETURNS: > + * Found address on success, %0 on failure. > + */ > +phys_addr_t __init_memblock > +__memblock_find_range(phys_addr_t start, phys_addr_t end, > + phys_addr_t size, phys_addr_t align, int nid) This func should be static as it must be an internal func. > +{ > + phys_addr_t this_start, this_end, cand; > + u64 i; > + > + for_each_free_mem_range(i, nid, &this_start, &this_end, NULL) { > + this_start = clamp(this_start, start, end); > + this_end = clamp(this_end, start, end); > + > + cand = round_up(this_start, align); > + if (cand < this_end && this_end - cand >= size) > + return cand; > + } > + return 0; > +} > + > +/** > + * __memblock_find_range_rev - find free area utility, in reverse order > + * @start: start of candidate range, can be %MEMBLOCK_ALLOC_ACCESSIBLE > + * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE} > + * @size: size of free area to find > + * @align: alignment of free area to find > + * @nid: nid of the free area to find, %MAX_NUMNODES for any node > + * > + * Utility called from memblock_find_in_range_node(), find free area from > + * higher address to lower address. > + * > + * RETURNS: > + * Found address on success, %0 on failure. > + */ > +phys_addr_t __init_memblock > +__memblock_find_range_rev(phys_addr_t start, phys_addr_t end, > + phys_addr_t size, phys_addr_t align, int nid) Ditto. > +{ > + phys_addr_t this_start, this_end, cand; > + u64 i; > + > + for_each_free_mem_range_reverse(i, nid, &this_start, &this_end, NULL) { > + this_start = clamp(this_start, start, end); > + this_end = clamp(this_end, start, end); > + > + /* > + * Just in case that (this_end - size) underflows and cause > + * (cand >= this_start) to be true incorrectly. > + */ > + if (this_end < size) > + break; > + > + cand = round_down(this_end - size, align); > + if (cand >= this_start) > + return cand; > + } > + return 0; > +} > + > +/** > * memblock_find_in_range_node - find free area in given range and node > * @start: start of candidate range, can be %MEMBLOCK_ALLOC_ACCESSIBLE > * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE} > @@ -110,9 +181,6 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start, > phys_addr_t end, phys_addr_t size, > phys_addr_t align, int nid) > { > - phys_addr_t this_start, this_end, cand; > - u64 i; > - > /* pump up @start and @end */ > if (start == MEMBLOCK_ALLOC_ACCESSIBLE) > start = memblock.current_limit_low; > @@ -123,18 +191,10 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start, > start = max_t(phys_addr_t, start, PAGE_SIZE); > end = max(start, end); > > - for_each_free_mem_range_reverse(i, nid, &this_start, &this_end, NULL) { > - this_start = clamp(this_start, start, end); > - this_end = clamp(this_end, start, end); > - > - if (this_end < size) > - continue; > - > - cand = round_down(this_end - size, align); > - if (cand >= this_start) > - return cand; > - } > - return 0; > + if (memblock.current_order == MEMBLOCK_ORDER_DEFAULT) This needs to use MEMBLOCK_ORDER_HIGH_TO_LOW since the code should be independent from the value of MEMBLOCK_ORDER_DEFAULT. Thanks, -Toshi -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org