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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2F2E1CA0FF0 for ; Mon, 1 Sep 2025 08:21:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 890C98E001A; Mon, 1 Sep 2025 04:21:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 840778E0014; Mon, 1 Sep 2025 04:21:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 756F08E001A; Mon, 1 Sep 2025 04:21:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 5E66B8E0014 for ; Mon, 1 Sep 2025 04:21:08 -0400 (EDT) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 01C7E11A18D for ; Mon, 1 Sep 2025 08:21:07 +0000 (UTC) X-FDA: 83839986216.02.E596EE4 Received: from baidu.com (mx24.baidu.com [111.206.215.185]) by imf08.hostedemail.com (Postfix) with ESMTP id 0CDAC160012 for ; Mon, 1 Sep 2025 08:21:04 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=baidu.com; spf=pass (imf08.hostedemail.com: domain of lirongqing@baidu.com designates 111.206.215.185 as permitted sender) smtp.mailfrom=lirongqing@baidu.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1756714866; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding:in-reply-to: references; bh=3ZMDLAHIEP3phT5r/rTd+vCBfZgv58EebSfqWadqOyM=; b=Uv/dn3KlManvnTuV7P4L+8SRUMAm7s5VQjyLzFL+FdSj6aEI/cW+DT5wNzMZ8ojDXeDa7+ 7X75uOfZ/L3vMINFDypjQ2LQLacZvnrzKKyy2urx7RuMU/F9rDIHH9CiIY7WBQ6DqYIR4z BWk8UAWwSPuHzie69jne2U4cKcuqiEU= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1756714866; a=rsa-sha256; cv=none; b=r5CH4y8Uu4e1aM8OP+vgfLP8UH/VXS2Nx62MPX8ghybFgcfh5/0/CSB00KPWn1Ny2eHnsZ vzJiCpFpwaY7WtMC/KxxHKLVMo3nLKg71/T2YJCkSKBM/NAiU6CLj3k3o/OPo08fL+Wotu 9/uPbILSgi+7FbOWujtwg2Ggw/b6IBw= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=baidu.com; spf=pass (imf08.hostedemail.com: domain of lirongqing@baidu.com designates 111.206.215.185 as permitted sender) smtp.mailfrom=lirongqing@baidu.com From: lirongqing To: , , , , , , CC: Li RongQing Subject: [PATCH][v4] mm/hugetlb: retry to allocate for early boot hugepage allocation Date: Mon, 1 Sep 2025 16:20:52 +0800 Message-ID: <20250901082052.3247-1-lirongqing@baidu.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.127.73.8] X-ClientProxiedBy: bjkjy-exc4.internal.baidu.com (172.31.50.48) To bjkjy-exc3.internal.baidu.com (172.31.50.47) X-FEAS-Client-IP: 172.31.50.47 X-FE-Policy-ID: 52:10:53:SYSTEM X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 0CDAC160012 X-Stat-Signature: 7z1xbmixyz4cwtbuxz9eqyx31hyskggd X-HE-Tag: 1756714864-493912 X-HE-Meta: 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 J7aSY8m8 76V04Wkq9faC+LNALqLp3gGwjho/fLBBj12XUhJH8UIUBywZ2vQuag6IYScCAXzx/y+C9MY/pBjcgeHR9AvtRiibI+ljSunHhqlmms0T1lrHQIyK7Nvn1GQWyhleNCZaIO8kb7wet//LmS+8gW73joDfUtGkc+WPxRWpD5JPl+Z1k9Gs= 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: List-Subscribe: List-Unsubscribe: From: Li RongQing In cloud environments with massive hugepage reservations (95%+ of system RAM), single-attempt allocation during early boot often fails due to memory pressure. Commit 91f386bf0772 ("hugetlb: batch freeing of vmemmap pages") intensified this by deferring page frees, increase peak memory usage during allocation. Introduce a retry mechanism that leverages vmemmap optimization reclaim (~1.6% memory) when available. Upon initial allocation failure, the system retries until successful or no further progress is made, ensuring reliable hugepage allocation while preserving batched vmemmap freeing benefits. Testing on a 256G machine allocating 252G of hugepages: Before: 128056/129024 hugepages allocated After: Successfully allocated all 129024 hugepages Suggested-by: David Hildenbrand Signed-off-by: Li RongQing --- Diff with v3: rewrite comment Diff with v2: auto retry mechanism Diff with v1: add log if two-phase hugepage allocation is triggered add the knod to control split ratio mm/hugetlb.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 753f99b..af7c36f 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3589,10 +3589,9 @@ static unsigned long __init hugetlb_pages_alloc_boot(struct hstate *h) unsigned long jiffies_start; unsigned long jiffies_end; + unsigned long remaining; job.thread_fn = hugetlb_pages_alloc_boot_node; - job.start = 0; - job.size = h->max_huge_pages; /* * job.max_threads is 25% of the available cpu threads by default. @@ -3616,10 +3615,29 @@ static unsigned long __init hugetlb_pages_alloc_boot(struct hstate *h) } job.max_threads = hugepage_allocation_threads; - job.min_chunk = h->max_huge_pages / hugepage_allocation_threads; jiffies_start = jiffies; - padata_do_multithreaded(&job); + do { + remaining = h->max_huge_pages - h->nr_huge_pages; + + job.start = h->nr_huge_pages; + job.size = remaining; + job.min_chunk = remaining / hugepage_allocation_threads; + padata_do_multithreaded(&job); + + if (h->nr_huge_pages == h->max_huge_pages) + break; + + /* + * Retry only if the vmemmap optimization might have been able to free + * some memory back to the system. + */ + if (!hugetlb_vmemmap_optimizable(h)) + break; + + /* Continue if progress was made in last iteration */ + } while (remaining != (h->max_huge_pages - h->nr_huge_pages)); + jiffies_end = jiffies; pr_info("HugeTLB: allocation took %dms with hugepage_allocation_threads=%ld\n", -- 2.9.4