From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4627DBF0.1080303@redhat.com> Date: Thu, 19 Apr 2007 17:15:28 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH] lazy freeing of memory through MADV_FREE 2/2 References: <46247427.6000902@redhat.com> In-Reply-To: <46247427.6000902@redhat.com> Content-Type: multipart/mixed; boundary="------------080907040107030804000708" Sender: owner-linux-mm@kvack.org Return-Path: To: Jakub Jelinek Cc: Andrew Morton , linux-kernel , linux-mm List-ID: This is a multi-part message in MIME format. --------------080907040107030804000708 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Restore MADV_DONTNEED to its original Linux behaviour. This is still not the same behaviour as POSIX, but applications may be depending on the Linux behaviour already. Besides, glibc catches POSIX_MADV_DONTNEED and makes sure nothing is done... Signed-off-by: Rik van Riel --- This is to be applied over of the original MADV_FREE patch. It turns out that the current glibc patch already falls back to MADV_DONTNEED if it gets an -EINVAL. --------------080907040107030804000708 Content-Type: text/x-patch; name="linux-2.6-madv-dontneed-restore.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="linux-2.6-madv-dontneed-restore.patch" --- linux-2.6.20.x86_64/mm/madvise.c.madv_free 2007-04-19 16:46:22.000000000 -0400 +++ linux-2.6.20.x86_64/mm/madvise.c 2007-04-19 16:52:19.000000000 -0400 @@ -130,7 +130,8 @@ static long madvise_willneed(struct vm_a */ static long madvise_dontneed(struct vm_area_struct * vma, struct vm_area_struct ** prev, - unsigned long start, unsigned long end) + unsigned long start, unsigned long end, + int behavior) { *prev = vma; if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP)) @@ -142,12 +143,14 @@ static long madvise_dontneed(struct vm_a .last_index = ULONG_MAX, }; zap_page_range(vma, start, end - start, &details); - } else { + } else if (behavior == MADV_FREE) { struct zap_details details = { .madv_free = 1, }; zap_page_range(vma, start, end - start, &details); - } + } else /* behavior == MADV_DONTNEED */ + zap_page_range(vma, start, end - start, NULL); + return 0; } @@ -219,10 +222,9 @@ madvise_vma(struct vm_area_struct *vma, error = madvise_willneed(vma, prev, start, end); break; - /* FIXME: POSIX says that MADV_DONTNEED cannot throw away data. */ case MADV_DONTNEED: case MADV_FREE: - error = madvise_dontneed(vma, prev, start, end); + error = madvise_dontneed(vma, prev, start, end, behavior); break; default: --------------080907040107030804000708-- -- 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