Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756538AbbEUPty (ORCPT ); Thu, 21 May 2015 11:49:54 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:31643 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756516AbbEUPtv (ORCPT ); Thu, 21 May 2015 11:49:51 -0400 From: Mike Kravetz To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Dave Hansen , Naoya Horiguchi , David Rientjes , Hugh Dickins , Davidlohr Bueso , Aneesh Kumar , Hillf Danton , Christoph Hellwig , Mike Kravetz Subject: [RFC v3 PATCH 04/10] mm/hugetlb: expose hugetlb fault mutex for use by fallocate Date: Thu, 21 May 2015 08:47:38 -0700 Message-Id: <1432223264-4414-5-git-send-email-mike.kravetz@oracle.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1432223264-4414-1-git-send-email-mike.kravetz@oracle.com> References: <1432223264-4414-1-git-send-email-mike.kravetz@oracle.com> X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2633 Lines: 75 hugetlb page faults are currently synchronized by the table of mutexes (htlb_fault_mutex_table). fallocate code will need to synchronize with the page fault code when it allocates or deletes pages. Expose interfaces so that fallocate operations can be synchronized with page faults. Signed-off-by: Mike Kravetz --- include/linux/hugetlb.h | 3 +++ mm/hugetlb.c | 23 ++++++++++++++++++++++- 2 files changed, 25 insertions(+), 1 deletion(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index fd337f2..d0d033e 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -82,6 +82,9 @@ void putback_active_hugepage(struct page *page); bool is_hugepage_active(struct page *page); void free_huge_page(struct page *page); void hugetlb_fix_reserve_counts(struct inode *inode, bool restore_reserve); +u32 hugetlb_fault_mutex_shared_hash(struct address_space *mapping, pgoff_t idx); +void hugetlb_fault_mutex_lock(u32 hash); +void hugetlb_fault_mutex_unlock(u32 hash); #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud); diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 620cc9e..df0d32a 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3183,7 +3183,8 @@ static u32 fault_mutex_hash(struct hstate *h, struct mm_struct *mm, unsigned long key[2]; u32 hash; - if (vma->vm_flags & VM_SHARED) { + /* !vma implies this was called from hugetlbfs fallocate code */ + if (!vma || vma->vm_flags & VM_SHARED) { key[0] = (unsigned long) mapping; key[1] = idx; } else { @@ -3209,6 +3210,26 @@ static u32 fault_mutex_hash(struct hstate *h, struct mm_struct *mm, } #endif +/* + * Interfaces to the fault mutex routines for use by hugetlbfs + * fallocate code. Faults must be synchronized with page adds or + * deletes by fallocate. fallocate only deals with shared mappings. + */ +u32 hugetlb_fault_mutex_shared_hash(struct address_space *mapping, pgoff_t idx) +{ + return fault_mutex_hash(NULL, NULL, NULL, mapping, idx, 0); +} + +void hugetlb_fault_mutex_lock(u32 hash) +{ + mutex_lock(&htlb_fault_mutex_table[hash]); +} + +void hugetlb_fault_mutex_unlock(u32 hash) +{ + mutex_unlock(&htlb_fault_mutex_table[hash]); +} + int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, unsigned int flags) { -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/