From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id 466626B0069 for ; Wed, 30 Nov 2016 22:11:14 -0500 (EST) Received: by mail-pf0-f197.google.com with SMTP id c4so333426333pfb.7 for ; Wed, 30 Nov 2016 19:11:14 -0800 (PST) Received: from out4435.biz.mail.alibaba.com (out4435.biz.mail.alibaba.com. [47.88.44.35]) by mx.google.com with ESMTP id 90si38505924pla.214.2016.11.30.19.11.11 for ; Wed, 30 Nov 2016 19:11:13 -0800 (PST) Reply-To: "Hillf Danton" From: "Hillf Danton" References: <20161129112304.90056-1-kirill.shutemov@linux.intel.com> <20161129112304.90056-23-kirill.shutemov@linux.intel.com> <017501d24aee$d9a189c0$8ce49d40$@alibaba-inc.com> <20161130131534.3k35cigsn36d7ku6@black.fi.intel.com> In-Reply-To: <20161130131534.3k35cigsn36d7ku6@black.fi.intel.com> Subject: Re: [PATCHv5 22/36] mm, hugetlb: switch hugetlbfs to multi-order radix-tree entries Date: Thu, 01 Dec 2016 11:10:52 +0800 Message-ID: <018c01d24b80$86b85490$9428fdb0$@alibaba-inc.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Language: zh-cn Sender: owner-linux-mm@kvack.org List-ID: To: "'Kirill A. Shutemov'" 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 Wednesday, November 30, 2016 9:16 PM Kirill A. Shutemov wrote: > 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. > You are right. I missed that critical point. thanks Hillf -- 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