From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f41.google.com (mail-oi0-f41.google.com [209.85.218.41]) by kanga.kvack.org (Postfix) with ESMTP id 7D3496B0032 for ; Fri, 17 Apr 2015 13:11:52 -0400 (EDT) Received: by oiko83 with SMTP id o83so80507641oik.1 for ; Fri, 17 Apr 2015 10:11:52 -0700 (PDT) Received: from userp1040.oracle.com (userp1040.oracle.com. [156.151.31.81]) by mx.google.com with ESMTPS id sw6si8371841obc.36.2015.04.17.10.11.51 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 17 Apr 2015 10:11:51 -0700 (PDT) Message-ID: <55313ECD.3050604@oracle.com> Date: Fri, 17 Apr 2015 10:11:41 -0700 From: Mike Kravetz MIME-Version: 1.0 Subject: Re: [RFC PATCH 4/4] mm: madvise allow remove operation for hugetlbfs References: <00e601d078da$9e762190$db6264b0$@alibaba-inc.com> <00ef01d078dd$96bfc480$c43f4d80$@alibaba-inc.com> In-Reply-To: <00ef01d078dd$96bfc480$c43f4d80$@alibaba-inc.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Hillf Danton , 'Dave Hansen' Cc: linux-kernel , linux-mm@kvack.org, Michal Hocko On 04/17/2015 12:10 AM, Hillf Danton wrote: >> >> Now that we have hole punching support for hugetlbfs, we can >> also support the MADV_REMOVE interface to it. >> >> Signed-off-by: Dave Hansen >> Signed-off-by: Mike Kravetz >> --- >> mm/madvise.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/mm/madvise.c b/mm/madvise.c >> index d551475..c4a1027 100644 >> --- a/mm/madvise.c >> +++ b/mm/madvise.c >> @@ -299,7 +299,7 @@ static long madvise_remove(struct vm_area_struct *vma, >> >> *prev = NULL; /* tell sys_madvise we drop mmap_sem */ >> >> - if (vma->vm_flags & (VM_LOCKED | VM_HUGETLB)) >> + if (vma->vm_flags & VM_LOCKED) >> return -EINVAL; >> >> f = vma->vm_file; >> -- >> 2.1.0 > > After the above change offset is computed, > > offset = (loff_t)(start - vma->vm_start) > + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); > > and I wonder if it is correct for huge page mapping. I think it will be correct. The above will be a (base) page size aligned offset into the file. This offset will be huge page aligned in the fallocate hole punch code. /* * For hole punch round up the beginning offset of the hole and * round down the end. */ hole_start = (offset + hpage_size - 1) & ~huge_page_mask(h); hole_end = (offset + len - (hpage_size - 1)) * ~huge_page_mask(h); Was the alignment your concern, or something else? -- Mike Kravetz -- 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