Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755000AbbHLJf1 (ORCPT ); Wed, 12 Aug 2015 05:35:27 -0400 Received: from blu004-omc1s20.hotmail.com ([65.55.116.31]:58081 "EHLO BLU004-OMC1S20.hotmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754947AbbHLJfZ (ORCPT ); Wed, 12 Aug 2015 05:35:25 -0400 X-TMN: [CtRjd4PEkVReezDQ8S6rKZuHr3vaG7P2] X-Originating-Email: [wanpeng.li@hotmail.com] Message-ID: Subject: Re: [PATCH v2 5/5] mm/hwpoison: replace most of put_page in memory error handling by put_hwpoison_page To: Naoya Horiguchi References: <1439206103-86829-1-git-send-email-wanpeng.li@hotmail.com> <20150812085525.GD32192@hori1.linux.bs1.fc.nec.co.jp> CC: Andrew Morton , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" From: Wanpeng Li Date: Wed, 12 Aug 2015 17:35:18 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:38.0) Gecko/20100101 Thunderbird/38.0.1 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/mixed; boundary="------------070009020307080301070305" X-OriginalArrivalTime: 12 Aug 2015 09:35:23.0092 (UTC) FILETIME=[36358940:01D0D4E2] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4450 Lines: 92 --------------070009020307080301070305 Content-Type: text/plain; charset="iso-2022-jp" Content-Transfer-Encoding: 7bit On 8/12/15 5:13 PM, Wanpeng Li wrote: > On 8/12/15 4:55 PM, Naoya Horiguchi wrote: >> On Mon, Aug 10, 2015 at 07:28:23PM +0800, Wanpeng Li wrote: >>> Replace most of put_page in memory error handling by put_hwpoison_page, >>> except the ones at the front of soft_offline_page since the page maybe >>> THP page and the get refcount in madvise_hwpoison is against the single >>> 4KB page instead of the logic in get_hwpoison_page. >>> >>> Signed-off-by: Wanpeng Li >> # Sorry for my late response. >> >> If I read correctly, get_user_pages_fast() (called by madvise_hwpoison) >> for a THP tail page takes a refcount from each of head and tail page. >> gup_huge_pmd() does this in the fast path, and get_page_foll() does this >> in the slow path (maybe via the following code path) >> >> get_user_pages_unlocked >> __get_user_pages_unlocked >> __get_user_pages_locked >> __get_user_pages >> follow_page_mask >> follow_trans_huge_pmd (with FOLL_GET set) >> get_page_foll >> >> So this should be equivalent to what get_hwpoison_page() does for thp pages >> with regard to refcounting. >> >> And I'm expecting that a refcount taken by get_hwpoison_page() is released >> by put_hwpoison_page() even if the page's status is changed during error >> handling (the typical (or only?) case is successful thp split.) > Indeed. :-) > >> So I think you can apply put_hwpoison_page() for 3 more callsites in >> mm/memory-failure.c. >> - MF_MSG_POISONED_HUGE case > I have already done this in my patch. > >> - "soft offline: %#lx page already poisoned" case (you mentioned above) >> - "soft offline: %#lx: failed to split THP" case (you mentioned above) > You are right, I will send a patch rebased on this one since they are > merged. The fix patch is in attachment. :) Regards, Wanpeng Li --------------070009020307080301070305 Content-Type: text/plain; charset="UTF-8"; x-mac-type=0; x-mac-creator=0; name="0001-mm-hwpoison-mm-hwpoison-replace-most-of-put_page-in-.patch" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename*0="0001-mm-hwpoison-mm-hwpoison-replace-most-of-put_page-in-.pa"; filename*1="tch" RnJvbSAzZDgzYzQwY2MzZjZkNDA4ODNhYWJmOWY2MDMzY2Q5ZDc4ZDExN2I1IE1vbiBTZXAg MTcgMDA6MDA6MDAgMjAwMQpGcm9tOiBXYW5wZW5nIExpIDx3YW5wZW5nLmxpQGhvdG1haWwu Y29tPgpEYXRlOiBXZWQsIDEyIEF1ZyAyMDE1IDE3OjMxOjQyICswODAwClN1YmplY3Q6IFtQ QVRDSF0gbW0vaHdwb2lzb246IHJlcGxhY2UgbW9zdCBvZiBwdXRfcGFnZSBpbiBtZW1vcnkg ZXJyb3IgaGFuZGxpbmcgYnkgcHV0X2h3cG9pc29uX3BhZ2UgZml4CgpOb3RlOiBUaGUgcGF0 Y2ggZGVzY3JpcHRpb24gb2Ygb3JpZ2luYWwgcGF0Y2ggIm1tL2h3cG9pc29uOiByZXBsYWNl IG1vc3Qgb2YgCnB1dF9wYWdlIGluIG1lbW9yeSBlcnJvciBoYW5kbGluZyBieSBwdXRfaHdw b2lzb25fcGFnZSIgc2hvdWxkIGJlIHJlcGxhY2VkIGJ5CiJSZXBsYWNlIG1vc3Qgb2YgcHV0 X3BhZ2UoKSBpbiBtZW1vcnkgZXJyb3IgaGFuZGxpbmcgYnkgcHV0X2h3cG9pc29uX3BhZ2Uo KSIuCgpTaWduZWQtb2ZmLWJ5OiBXYW5wZW5nIExpIDx3YW5wZW5nLmxpQGhvdG1haWwuY29t PgotLS0KIG1tL21lbW9yeS1mYWlsdXJlLmMgfCAgICA0ICsrLS0KIDEgZmlsZXMgY2hhbmdl ZCwgMiBpbnNlcnRpb25zKCspLCAyIGRlbGV0aW9ucygtKQoKZGlmZiAtLWdpdCBhL21tL21l bW9yeS1mYWlsdXJlLmMgYi9tbS9tZW1vcnktZmFpbHVyZS5jCmluZGV4IDBhY2FmZWUuLmQz NzgxODggMTAwNjQ0Ci0tLSBhL21tL21lbW9yeS1mYWlsdXJlLmMKKysrIGIvbW0vbWVtb3J5 LWZhaWx1cmUuYwpAQCAtMTcyNyw3ICsxNzI3LDcgQEAgaW50IHNvZnRfb2ZmbGluZV9wYWdl KHN0cnVjdCBwYWdlICpwYWdlLCBpbnQgZmxhZ3MpCiAJaWYgKFBhZ2VIV1BvaXNvbihwYWdl KSkgewogCQlwcl9pbmZvKCJzb2Z0IG9mZmxpbmU6ICUjbHggcGFnZSBhbHJlYWR5IHBvaXNv bmVkXG4iLCBwZm4pOwogCQlpZiAoZmxhZ3MgJiBNRl9DT1VOVF9JTkNSRUFTRUQpCi0JCQlw dXRfcGFnZShwYWdlKTsKKwkJCXB1dF9od3BvaXNvbl9wYWdlKHBhZ2UpOwogCQlyZXR1cm4g LUVCVVNZOwogCX0KIAlpZiAoIVBhZ2VIdWdlKHBhZ2UpICYmIFBhZ2VUcmFuc0h1Z2UoaHBh Z2UpKSB7CkBAIC0xNzM1LDcgKzE3MzUsNyBAQCBpbnQgc29mdF9vZmZsaW5lX3BhZ2Uoc3Ry dWN0IHBhZ2UgKnBhZ2UsIGludCBmbGFncykKIAkJCXByX2luZm8oInNvZnQgb2ZmbGluZTog JSNseDogZmFpbGVkIHRvIHNwbGl0IFRIUFxuIiwKIAkJCQlwZm4pOwogCQkJaWYgKGZsYWdz ICYgTUZfQ09VTlRfSU5DUkVBU0VEKQotCQkJCXB1dF9wYWdlKHBhZ2UpOworCQkJCXB1dF9o d3BvaXNvbl9wYWdlKHBhZ2UpOwogCQkJcmV0dXJuIC1FQlVTWTsKIAkJfQogCX0KLS0gCjEu Ny4xCgo= --------------070009020307080301070305-- -- 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/