From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f72.google.com (mail-pg0-f72.google.com [74.125.83.72]) by kanga.kvack.org (Postfix) with ESMTP id 7233E6B025E for ; Wed, 30 Nov 2016 08:16:25 -0500 (EST) Received: by mail-pg0-f72.google.com with SMTP id g186so22605184pgc.2 for ; Wed, 30 Nov 2016 05:16:25 -0800 (PST) Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTPS id z63si64449416pff.293.2016.11.30.05.16.24 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 30 Nov 2016 05:16:24 -0800 (PST) Date: Wed, 30 Nov 2016 16:15:34 +0300 From: "Kirill A. Shutemov" Subject: Re: [PATCHv5 22/36] mm, hugetlb: switch hugetlbfs to multi-order radix-tree entries Message-ID: <20161130131534.3k35cigsn36d7ku6@black.fi.intel.com> References: <20161129112304.90056-1-kirill.shutemov@linux.intel.com> <20161129112304.90056-23-kirill.shutemov@linux.intel.com> <017501d24aee$d9a189c0$8ce49d40$@alibaba-inc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <017501d24aee$d9a189c0$8ce49d40$@alibaba-inc.com> Sender: owner-linux-mm@kvack.org List-ID: To: Hillf Danton Cc: 'Theodore Ts'o' , 'Andreas Dilger' , 'Jan Kara' , 'Andrew Morton' , 'Alexander Viro' , 'Hugh Dickins' , 'Andrea Arcangeli' , 'Dave Hansen' , 'Vlastimil Babka' , 'Matthew Wilcox' , 'Ross Zwisler' , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org, 'Naoya Horiguchi' On Wed, Nov 30, 2016 at 05:48:05PM +0800, Hillf Danton wrote: > On Tuesday, November 29, 2016 7:23 PM Kirill A. Shutemov wrote: > > @@ -607,10 +605,10 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset, > > } > > > > /* Set numa allocation policy based on index */ > > - hugetlb_set_vma_policy(&pseudo_vma, inode, index); > > + hugetlb_set_vma_policy(&pseudo_vma, inode, index >> huge_page_order(h)); > > > > /* addr is the offset within the file (zero based) */ > > - addr = index * hpage_size; > > + addr = index << PAGE_SHIFT & ~huge_page_mask(h); > > > > /* mutex taken here, fault path and hole punch */ > > hash = hugetlb_fault_mutex_hash(h, mm, &pseudo_vma, mapping, > > Seems we can't use index in computing hash as long as it isn't in huge page size. Look at changes in hugetlb_fault_mutex_hash(): we shift the index right by huge_page_order(), before calculating the hash. I don't see a problem here. -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org