From patchwork Fri Oct 21 16:36:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Houghton X-Patchwork-Id: 13015074 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]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6339AFA373E for ; Fri, 21 Oct 2022 16:37:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 09E588E0008; Fri, 21 Oct 2022 12:37:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EC3668E0001; Fri, 21 Oct 2022 12:37:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CEF4E8E0008; Fri, 21 Oct 2022 12:37:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id B56268E0001 for ; Fri, 21 Oct 2022 12:37:22 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 8044F1A1135 for ; Fri, 21 Oct 2022 16:37:22 +0000 (UTC) X-FDA: 80045511924.20.7037E4E Received: from mail-vs1-f73.google.com (mail-vs1-f73.google.com [209.85.217.73]) by imf14.hostedemail.com (Postfix) with ESMTP id 26BEA100026 for ; Fri, 21 Oct 2022 16:37:21 +0000 (UTC) Received: by mail-vs1-f73.google.com with SMTP id 124-20020a671082000000b0039b07671c7aso1059315vsq.13 for ; Fri, 21 Oct 2022 09:37:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=34cx5eEOWWMEza3+3K1vLVCCrFvx1bz9vEUMrzq2ytU=; b=Sp9ejFIjwkTD2k7b5O35d/eTr3qFaL4Cu0+Y3Jqen1+jW42rNvItxKaNURZz5TSKk7 x35Bvv5PH68z6pCQYFbhWyoyGgG4rzUpeOPbjmYrzgvXuzuUNcyvX4/Otvfkuiq5+cZv HHQynZVto3uDixtcVQsCf3qWQvklcY23DsStSgC2qGnXAGQ/l0stiqvSXSvt9oZVTDkE Caber1o4FewbpJvcwU1yEnRVdmKdy2XZSnVqN1DFbOLIkZI+hKbcR55fyjn4Og0CJ7M/ x13b8bjYpqhnO2fokhLpSAWC6h6Udyc8I00LhZRGAFNopGb6wpiImE12TuoAvXq6t9Ke 1k4A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=34cx5eEOWWMEza3+3K1vLVCCrFvx1bz9vEUMrzq2ytU=; b=O1LSqQsoxEa/98CjBfxgKUFCi55nFJSCNAPOiIgmCpf+TxW+Vs7zbPRtkhSOLQsAkr hJ5UE9o9GaioGfuZAJ8M7svUN9pEjt8PnPpVhZDdXgEoCF9Y5fNkVR50zu/PFOnLXemG yPrI14NBhqrTNMDoT16P9nd/SEU43M9gmQFFnG3HMAsVLCKJWXv46rE1ZcU7IC6inohw LwByMKoYIKoFgWbYqnn+3HgyXYYk3NxHfVe9kq3LG4GOUKn0ODpQZn56assnJxn+pwA3 uig2AjUborLWoq8kUi0DuzGlD/+yjOiENybNXxGuz0mrEDUC5tm0Qlp6SIqP1lCqJpUg i1Fw== X-Gm-Message-State: ACrzQf0uRgN9WQR6ybQ9UjUuamBhGMQ0MHPrZ+AssXlC8aLZpILnbqtI nlxJ8kMSjiuHDHV58Qkard9/9JZ3SZlmOYU1 X-Google-Smtp-Source: AMsMyM6Mvo2qQVK8sdSIbcMVnfOhwFg4FhU4eWPB/UUGtomewuseawpOfNBtO35uLxun2jYxXKf3dRRjIA99NUXN X-Received: from jthoughton.c.googlers.com ([fda3:e722:ac3:cc00:14:4d90:c0a8:2a4f]) (user=jthoughton job=sendgmr) by 2002:a67:fa59:0:b0:3a7:7516:b43b with SMTP id j25-20020a67fa59000000b003a77516b43bmr14278433vsq.83.1666370241512; Fri, 21 Oct 2022 09:37:21 -0700 (PDT) Date: Fri, 21 Oct 2022 16:36:21 +0000 In-Reply-To: <20221021163703.3218176-1-jthoughton@google.com> Mime-Version: 1.0 References: <20221021163703.3218176-1-jthoughton@google.com> X-Mailer: git-send-email 2.38.0.135.g90850a2211-goog Message-ID: <20221021163703.3218176-6-jthoughton@google.com> Subject: [RFC PATCH v2 05/47] hugetlb: make hugetlb_vma_lock_alloc return its failure reason From: James Houghton To: Mike Kravetz , Muchun Song , Peter Xu Cc: David Hildenbrand , David Rientjes , Axel Rasmussen , Mina Almasry , "Zach O'Keefe" , Manish Mishra , Naoya Horiguchi , "Dr . David Alan Gilbert" , "Matthew Wilcox (Oracle)" , Vlastimil Babka , Baolin Wang , Miaohe Lin , Yang Shi , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, James Houghton ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1666370242; 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:in-reply-to:references:references:dkim-signature; bh=34cx5eEOWWMEza3+3K1vLVCCrFvx1bz9vEUMrzq2ytU=; b=fi9Sq/re+NHFjELxDOxQFUlolivAOMvsONqYGCTIfHry94PDVZ96KJnMfyOug/xRjLSxMz 2PT2FKgB5qh4lKnYFo5Q1bbKiPVIlaGKQ29rk+wsAJn6rQPBrtwkqiMCwCbs1aJeb+27OD mOqyGWG71QEUgtnO8kWS1OKRnXazBns= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=Sp9ejFIj; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf14.hostedemail.com: domain of 3wcpSYwoKCMIr1pw2op1wvowwotm.kwutqv25-uus3iks.wzo@flex--jthoughton.bounces.google.com designates 209.85.217.73 as permitted sender) smtp.mailfrom=3wcpSYwoKCMIr1pw2op1wvowwotm.kwutqv25-uus3iks.wzo@flex--jthoughton.bounces.google.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1666370242; a=rsa-sha256; cv=none; b=CCkYb4uH9m3ibc7IOOkJLFSx8gj5Qna8YBmOldjzZvzRi25qkhmEjillXUsE6BX1CXFs7j cl7vLxTuGmV2zckJ5h1sgBtxJnMn/rPuEgXTTGoWJAjHSiV2RjIuSUxi1lf66ZArxjjqPE cNQL2c/ZjODZlnWamamnLvIGT6HRI5M= X-Rspam-User: X-Rspamd-Queue-Id: 26BEA100026 X-Stat-Signature: 7tnu6fiqpb7p5oksezrjohityacgcy7t Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=Sp9ejFIj; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf14.hostedemail.com: domain of 3wcpSYwoKCMIr1pw2op1wvowwotm.kwutqv25-uus3iks.wzo@flex--jthoughton.bounces.google.com designates 209.85.217.73 as permitted sender) smtp.mailfrom=3wcpSYwoKCMIr1pw2op1wvowwotm.kwutqv25-uus3iks.wzo@flex--jthoughton.bounces.google.com X-Rspamd-Server: rspam07 X-HE-Tag: 1666370241-790313 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: Currently hugetlb_vma_lock_alloc doesn't return anything, as there is no need: if it fails, PMD sharing won't be enabled. However, HGM requires that the VMA lock exists, so we need to verify that hugetlb_vma_lock_alloc actually succeeded. If hugetlb_vma_lock_alloc fails, then we can pass that up to the caller that is attempting to enable HGM. Signed-off-by: James Houghton --- mm/hugetlb.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 52cec5b0789e..dc82256b89dd 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -92,7 +92,7 @@ struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp; /* Forward declaration */ static int hugetlb_acct_memory(struct hstate *h, long delta); static void hugetlb_vma_lock_free(struct vm_area_struct *vma); -static void hugetlb_vma_lock_alloc(struct vm_area_struct *vma); +static int hugetlb_vma_lock_alloc(struct vm_area_struct *vma); static void __hugetlb_vma_unlock_write_free(struct vm_area_struct *vma); static inline bool subpool_is_free(struct hugepage_subpool *spool) @@ -7001,17 +7001,17 @@ static void hugetlb_vma_lock_free(struct vm_area_struct *vma) } } -static void hugetlb_vma_lock_alloc(struct vm_area_struct *vma) +static int hugetlb_vma_lock_alloc(struct vm_area_struct *vma) { struct hugetlb_vma_lock *vma_lock; /* Only establish in (flags) sharable vmas */ if (!vma || !(vma->vm_flags & VM_MAYSHARE)) - return; + return -EINVAL; - /* Should never get here with non-NULL vm_private_data */ + /* We've already allocated the lock. */ if (vma->vm_private_data) - return; + return 0; vma_lock = kmalloc(sizeof(*vma_lock), GFP_KERNEL); if (!vma_lock) { @@ -7026,13 +7026,14 @@ static void hugetlb_vma_lock_alloc(struct vm_area_struct *vma) * allocation failure. */ pr_warn_once("HugeTLB: unable to allocate vma specific lock\n"); - return; + return -ENOMEM; } kref_init(&vma_lock->refs); init_rwsem(&vma_lock->rw_sema); vma_lock->vma = vma; vma->vm_private_data = vma_lock; + return 0; } /* @@ -7160,8 +7161,9 @@ static void hugetlb_vma_lock_free(struct vm_area_struct *vma) { } -static void hugetlb_vma_lock_alloc(struct vm_area_struct *vma) +static int hugetlb_vma_lock_alloc(struct vm_area_struct *vma) { + return 0; } pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma,