From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49ABEC433F5 for ; Thu, 14 Oct 2021 08:59:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 332E4610EA for ; Thu, 14 Oct 2021 08:59:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230231AbhJNJB3 (ORCPT ); Thu, 14 Oct 2021 05:01:29 -0400 Received: from szxga03-in.huawei.com ([45.249.212.189]:25185 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230222AbhJNJBT (ORCPT ); Thu, 14 Oct 2021 05:01:19 -0400 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.56]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4HVNbH27Hzz8tfS; Thu, 14 Oct 2021 16:58:03 +0800 (CST) Received: from dggpemm500002.china.huawei.com (7.185.36.229) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Thu, 14 Oct 2021 16:59:11 +0800 Received: from [10.174.178.178] (10.174.178.178) by dggpemm500002.china.huawei.com (7.185.36.229) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Thu, 14 Oct 2021 16:59:10 +0800 Message-ID: <8fc5e1ae-a356-6225-2e50-cf0e5ee26208@huawei.com> Date: Thu, 14 Oct 2021 16:59:10 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.0.3 Subject: Re: [PATCH] mm/vmalloc: fix numa spreading for large hash tables To: Shakeel Butt CC: Andrew Morton , Nicholas Piggin , Linux MM , LKML , Eric Dumazet , "Kefeng Wang" , References: <20210928121040.2547407-1-chenwandun@huawei.com> From: Chen Wandun In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.178.178] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500002.china.huawei.com (7.185.36.229) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2021/10/14 5:46, Shakeel Butt 写道: > On Tue, Sep 28, 2021 at 5:03 AM Chen Wandun wrote: >> >> Eric Dumazet reported a strange numa spreading info in [1], and found >> commit 121e6f3258fe ("mm/vmalloc: hugepage vmalloc mappings") introduced >> this issue [2]. >> >> Dig into the difference before and after this patch, page allocation has >> some difference: >> >> before: >> alloc_large_system_hash >> __vmalloc >> __vmalloc_node(..., NUMA_NO_NODE, ...) >> __vmalloc_node_range >> __vmalloc_area_node >> alloc_page /* because NUMA_NO_NODE, so choose alloc_page branch */ >> alloc_pages_current >> alloc_page_interleave /* can be proved by print policy mode */ >> >> after: >> alloc_large_system_hash >> __vmalloc >> __vmalloc_node(..., NUMA_NO_NODE, ...) >> __vmalloc_node_range >> __vmalloc_area_node >> alloc_pages_node /* choose nid by nuam_mem_id() */ >> __alloc_pages_node(nid, ....) >> >> So after commit 121e6f3258fe ("mm/vmalloc: hugepage vmalloc mappings"), >> it will allocate memory in current node instead of interleaving allocate >> memory. >> >> [1] >> https://lore.kernel.org/linux-mm/CANn89iL6AAyWhfxdHO+jaT075iOa3XcYn9k6JJc7JR2XYn6k_Q@mail.gmail.com/ >> >> [2] >> https://lore.kernel.org/linux-mm/CANn89iLofTR=AK-QOZY87RdUZENCZUT4O6a0hvhu3_EwRMerOg@mail.gmail.com/ >> >> Fixes: 121e6f3258fe ("mm/vmalloc: hugepage vmalloc mappings") >> Reported-by: Eric Dumazet >> Signed-off-by: Chen Wandun >> --- >> mm/vmalloc.c | 33 ++++++++++++++++++++++++++------- >> 1 file changed, 26 insertions(+), 7 deletions(-) >> >> diff --git a/mm/vmalloc.c b/mm/vmalloc.c >> index f884706c5280..48e717626e94 100644 >> --- a/mm/vmalloc.c >> +++ b/mm/vmalloc.c >> @@ -2823,6 +2823,8 @@ vm_area_alloc_pages(gfp_t gfp, int nid, >> unsigned int order, unsigned int nr_pages, struct page **pages) >> { >> unsigned int nr_allocated = 0; >> + struct page *page; >> + int i; >> >> /* >> * For order-0 pages we make use of bulk allocator, if >> @@ -2833,6 +2835,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid, >> if (!order) { > > Can you please replace the above with if (!order && nid != NUMA_NO_NODE)? > >> while (nr_allocated < nr_pages) { >> unsigned int nr, nr_pages_request; >> + page = NULL; >> >> /* >> * A maximum allowed request is hard-coded and is 100 >> @@ -2842,9 +2845,23 @@ vm_area_alloc_pages(gfp_t gfp, int nid, >> */ >> nr_pages_request = min(100U, nr_pages - nr_allocated); >> > > Undo the following change in this if block. Yes, It seem like more simpler as you suggested, But it still have performance regression, I plan to change the following to consider both mempolcy and alloc_pages_bulk. Thanks, Wandun > >> - nr = alloc_pages_bulk_array_node(gfp, nid, >> - nr_pages_request, pages + nr_allocated); >> - >> + if (nid == NUMA_NO_NODE) { >> + for (i = 0; i < nr_pages_request; i++) { >> + page = alloc_page(gfp); >> + if (page) >> + pages[nr_allocated + i] = page; >> + else { >> + nr = i; >> + break; >> + } >> + } >> + if (i >= nr_pages_request) >> + nr = nr_pages_request; >> + } else { >> + nr = alloc_pages_bulk_array_node(gfp, nid, >> + nr_pages_request, >> + pages + nr_allocated); >> + } >> nr_allocated += nr; >> cond_resched(); >> >> @@ -2863,11 +2880,13 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > > Put the following line under "else if (order)" > >> gfp |= __GFP_COMP; >> >> /* High-order pages or fallback path if "bulk" fails. */ >> - while (nr_allocated < nr_pages) { > > Keep the following declarations inside the while loop. > >> - struct page *page; >> - int i; >> >> - page = alloc_pages_node(nid, gfp, order); >> + page = NULL; >> + while (nr_allocated < nr_pages) { >> + if (nid == NUMA_NO_NODE) >> + page = alloc_pages(gfp, order); >> + else >> + page = alloc_pages_node(nid, gfp, order); >> if (unlikely(!page)) >> break; >> >> -- >> 2.25.1 >> > . >