Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753757Ab3EUKug (ORCPT ); Tue, 21 May 2013 06:50:36 -0400 Received: from hydra.sisk.pl ([212.160.235.94]:42683 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752316Ab3EUKue (ORCPT ); Tue, 21 May 2013 06:50:34 -0400 From: "Rafael J. Wysocki" To: Xishi Qiu Cc: ACPI Devel Maling List , LKML , Greg Kroah-Hartman , Toshi Kani , Wen Congyang , Tang Chen , Yasuaki Ishimatsu , Andrew Morton , Jiang Liu , Vasilis Liaskovitis , linux-mm@kvack.org Subject: Re: [PATCH 4/5] ACPI / scan: Add second pass of companion offlining to hot-remove code Date: Tue, 21 May 2013 12:59:13 +0200 Message-ID: <5594351.7bIW5J5bfS@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.9.0+; KDE/4.9.5; x86_64; ; ) In-Reply-To: <519B238D.3070900@huawei.com> References: <2250271.rGYN6WlBxf@vostro.rjw.lan> <3662688.5fMZaG7XgD@vostro.rjw.lan> <519B238D.3070900@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2786 Lines: 87 On Tuesday, May 21, 2013 03:34:37 PM Xishi Qiu wrote: > On 2013/5/19 7:34, Rafael J. Wysocki wrote: > > > From: Rafael J. Wysocki > > > > As indicated by comments in mm/memory_hotplug.c:remove_memory(), > > if CONFIG_MEMCG is set, it may not be possible to offline all of the > > memory blocks held by one module (FRU) in one pass (because one of > > them may be used by the others to store page cgroup in that case > > and that block has to be offlined before the other ones). > > > > To handle that arguably corner case, add a second pass of companion > > device offlining to acpi_scan_hot_remove() and make it ignore errors > > returned in the first pass (and make it skip the second pass if the > > first one is successful). > > > > Signed-off-by: Rafael J. Wysocki > > --- > > drivers/acpi/scan.c | 67 ++++++++++++++++++++++++++++++++++++++-------------- > > 1 file changed, 50 insertions(+), 17 deletions(-) > > > > Index: linux-pm/drivers/acpi/scan.c > > =================================================================== > > --- linux-pm.orig/drivers/acpi/scan.c > > +++ linux-pm/drivers/acpi/scan.c > > @@ -131,6 +131,7 @@ static acpi_status acpi_bus_offline_comp > > { > > struct acpi_device *device = NULL; > > struct acpi_device_physical_node *pn; > > + bool second_pass = (bool)data; > > acpi_status status = AE_OK; > > > > if (acpi_bus_get_device(handle, &device)) > > @@ -141,15 +142,26 @@ static acpi_status acpi_bus_offline_comp > > list_for_each_entry(pn, &device->physical_node_list, node) { > > int ret; > > > > + if (second_pass) { > > + /* Skip devices offlined by the first pass. */ > > + if (pn->put_online) > > should it be "if (!pn->put_online)" ? No, I don't think so. pn->put_online set means that the device has been offlined by the first pass, so we don't need to try it in the second one. Thanks, Rafael > > + continue; > > + } else { > > + pn->put_online = false; > > + } > > ret = device_offline(pn->dev); > > if (acpi_force_hot_remove) > > continue; > > > > - if (ret < 0) { > > - status = AE_ERROR; > > - break; > > + if (ret >= 0) { > > + pn->put_online = !ret; > > + } else { > > + *ret_p = pn->dev; > > + if (second_pass) { > > + status = AE_ERROR; > > + break; > > + } > > } > > - pn->put_online = !ret; > > } > > > > mutex_unlock(&device->physical_node_lock); > > > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- 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/