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 X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0BC85C4320A for ; Mon, 2 Aug 2021 02:47:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9D5F161050 for ; Mon, 2 Aug 2021 02:47:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 9D5F161050 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 391206B0036; Sun, 1 Aug 2021 22:47:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 341066B005D; Sun, 1 Aug 2021 22:47:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 230206B006C; Sun, 1 Aug 2021 22:47:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0141.hostedemail.com [216.40.44.141]) by kanga.kvack.org (Postfix) with ESMTP id 09EC26B0036 for ; Sun, 1 Aug 2021 22:47:12 -0400 (EDT) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id B36951DE9B for ; Mon, 2 Aug 2021 02:47:11 +0000 (UTC) X-FDA: 78428603862.01.58A62BB Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by imf23.hostedemail.com (Postfix) with ESMTP id A1B809000703 for ; Mon, 2 Aug 2021 02:47:10 +0000 (UTC) Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4GdMkw0WYZzcjk4; Mon, 2 Aug 2021 10:43:36 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 2 Aug 2021 10:47:05 +0800 Received: from [10.174.177.243] (10.174.177.243) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 2 Aug 2021 10:47:04 +0800 Subject: Re: [PATCH v2 2/3] arm64: Support page mapping percpu first chunk allocator To: Catalin Marinas CC: Will Deacon , Andrey Ryabinin , Andrey Konovalov , Dmitry Vyukov , , , , , Greg Kroah-Hartman References: <20210720025105.103680-1-wangkefeng.wang@huawei.com> <20210720025105.103680-3-wangkefeng.wang@huawei.com> <20210801155302.GA29188@arm.com> From: Kefeng Wang Message-ID: Date: Mon, 2 Aug 2021 10:47:04 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20210801155302.GA29188@arm.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: A1B809000703 Authentication-Results: imf23.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=huawei.com; spf=pass (imf23.hostedemail.com: domain of wangkefeng.wang@huawei.com designates 45.249.212.188 as permitted sender) smtp.mailfrom=wangkefeng.wang@huawei.com X-Stat-Signature: zepbjjjtyk6mqbridsoi5gagweqfbf79 X-HE-Tag: 1627872430-33698 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 2021/8/1 23:53, Catalin Marinas wrote: > On Tue, Jul 20, 2021 at 10:51:04AM +0800, Kefeng Wang wrote: >> Percpu embedded first chunk allocator is the firstly option, but it >> could fails on ARM64, eg, >> "percpu: max_distance=0x5fcfdc640000 too large for vmalloc space 0x781fefff0000" >> "percpu: max_distance=0x600000540000 too large for vmalloc space 0x7dffb7ff0000" >> "percpu: max_distance=0x5fff9adb0000 too large for vmalloc space 0x5dffb7ff0000" >> >> then we could meet "WARNING: CPU: 15 PID: 461 at vmalloc.c:3087 pcpu_get_vm_areas+0x488/0x838", >> even the system could not boot successfully. >> >> Let's implement page mapping percpu first chunk allocator as a fallback >> to the embedding allocator to increase the robustness of the system. > It looks like x86, powerpc and sparc implement their own > setup_per_cpu_areas(). I had a quick look on finding some commonalities > but I think it's a lot more hassle to make a generic version out of them > (powerpc looks the simplest though). I think we could add a generic > variant with the arm64 support and later migrate other architectures to > it if possible. Ok, let's do it later, I could try to make some cleanup after the patchset is merged ;) > The patch looks ok to me otherwise but I'd need an ack from Greg as it > touches drivers/. the arch_numa is only used ARM64 and riscv, the NEED_PER_CPU_PAGE_FIRST_CHUNK is not enabled on RISCV, so it's no bad effect. > > BTW, do we need something similar for the non-NUMA > setup_per_cpu_areas()? I can see this patch only enables > NEED_PER_CPU_PAGE_FIRST_CHUNK if NUMA. > > Leaving the rest of the patch below for Greg. > >> Signed-off-by: Kefeng Wang >> --- >> arch/arm64/Kconfig | 4 ++ >> drivers/base/arch_numa.c | 82 +++++++++++++++++++++++++++++++++++----- >> 2 files changed, 76 insertions(+), 10 deletions(-) >> >> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig >> index b5b13a932561..eacb5873ded1 100644 >> --- a/arch/arm64/Kconfig >> +++ b/arch/arm64/Kconfig >> @@ -1045,6 +1045,10 @@ config NEED_PER_CPU_EMBED_FIRST_CHUNK >> def_bool y >> depends on NUMA >> >> +config NEED_PER_CPU_PAGE_FIRST_CHUNK >> + def_bool y >> + depends on NUMA >> + >> source "kernel/Kconfig.hz" >> >> config ARCH_SPARSEMEM_ENABLE >> diff --git a/drivers/base/arch_numa.c b/drivers/base/arch_numa.c >> index 4cc4e117727d..563b2013b75a 100644 >> --- a/drivers/base/arch_numa.c >> +++ b/drivers/base/arch_numa.c >> @@ -14,6 +14,7 @@ >> #include >> >> #include >> +#include >> >> struct pglist_data *node_data[MAX_NUMNODES] __read_mostly; >> EXPORT_SYMBOL(node_data); >> @@ -168,22 +169,83 @@ static void __init pcpu_fc_free(void *ptr, size_t size) >> memblock_free_early(__pa(ptr), size); >> } >> >> +#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK >> +static void __init pcpu_populate_pte(unsigned long addr) >> +{ >> + pgd_t *pgd = pgd_offset_k(addr); >> + p4d_t *p4d; >> + pud_t *pud; >> + pmd_t *pmd; >> + >> + p4d = p4d_offset(pgd, addr); >> + if (p4d_none(*p4d)) { >> + pud_t *new; >> + >> + new = memblock_alloc(PAGE_SIZE, PAGE_SIZE); >> + if (!new) >> + goto err_alloc; >> + p4d_populate(&init_mm, p4d, new); >> + } >> + >> + pud = pud_offset(p4d, addr); >> + if (pud_none(*pud)) { >> + pmd_t *new; >> + >> + new = memblock_alloc(PAGE_SIZE, PAGE_SIZE); >> + if (!new) >> + goto err_alloc; >> + pud_populate(&init_mm, pud, new); >> + } >> + >> + pmd = pmd_offset(pud, addr); >> + if (!pmd_present(*pmd)) { >> + pte_t *new; >> + >> + new = memblock_alloc(PAGE_SIZE, PAGE_SIZE); >> + if (!new) >> + goto err_alloc; >> + pmd_populate_kernel(&init_mm, pmd, new); >> + } >> + >> + return; >> + >> +err_alloc: >> + panic("%s: Failed to allocate %lu bytes align=%lx from=%lx\n", >> + __func__, PAGE_SIZE, PAGE_SIZE, PAGE_SIZE); >> +} >> +#endif >> + >> void __init setup_per_cpu_areas(void) >> { >> unsigned long delta; >> unsigned int cpu; >> - int rc; >> + int rc = -EINVAL; >> + >> + if (pcpu_chosen_fc != PCPU_FC_PAGE) { >> + /* >> + * Always reserve area for module percpu variables. That's >> + * what the legacy allocator did. >> + */ >> + rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, >> + PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, >> + pcpu_cpu_distance, >> + pcpu_fc_alloc, pcpu_fc_free); >> +#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK >> + if (rc < 0) >> + pr_warn("PERCPU: %s allocator failed (%d), falling back to page size\n", >> + pcpu_fc_names[pcpu_chosen_fc], rc); >> +#endif >> + } >> >> - /* >> - * Always reserve area for module percpu variables. That's >> - * what the legacy allocator did. >> - */ >> - rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, >> - PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, >> - pcpu_cpu_distance, >> - pcpu_fc_alloc, pcpu_fc_free); >> +#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK >> + if (rc < 0) >> + rc = pcpu_page_first_chunk(PERCPU_MODULE_RESERVE, >> + pcpu_fc_alloc, >> + pcpu_fc_free, >> + pcpu_populate_pte); >> +#endif >> if (rc < 0) >> - panic("Failed to initialize percpu areas."); >> + panic("Failed to initialize percpu areas (err=%d).", rc); >> >> delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; >> for_each_possible_cpu(cpu) >> -- >> 2.26.2 > . >