From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f200.google.com (mail-qk0-f200.google.com [209.85.220.200]) by kanga.kvack.org (Postfix) with ESMTP id 47E516B026F for ; Mon, 4 Dec 2017 06:51:40 -0500 (EST) Received: by mail-qk0-f200.google.com with SMTP id x185so11272939qka.1 for ; Mon, 04 Dec 2017 03:51:40 -0800 (PST) Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com. [148.163.156.1]) by mx.google.com with ESMTPS id w1si2120605qta.130.2017.12.04.03.51.39 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 04 Dec 2017 03:51:39 -0800 (PST) Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id vB4BoDnT098420 for ; Mon, 4 Dec 2017 06:51:38 -0500 Received: from e06smtp13.uk.ibm.com (e06smtp13.uk.ibm.com [195.75.94.109]) by mx0a-001b2d01.pphosted.com with ESMTP id 2en5jugxa8-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 04 Dec 2017 06:51:37 -0500 Received: from localhost by e06smtp13.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 4 Dec 2017 11:51:35 -0000 Date: Mon, 4 Dec 2017 11:51:29 +0000 From: Andrea Reale Subject: Re: [PATCH v2 4/5] mm: memory_hotplug: Add memory hotremove probe device References: <22d34fe30df0fbacbfceeb47e20cb1184af73585.1511433386.git.ar@linux.vnet.ibm.com> <20171130144905.ntpovhy66gekj6e6@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20171130144905.ntpovhy66gekj6e6@dhcp22.suse.cz> Message-Id: <20171204115129.GD6373@samekh> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, m.bielski@virtualopensystems.com, arunks@qti.qualcomm.com, mark.rutland@arm.com, scott.branden@broadcom.com, will.deacon@arm.com, qiuxishi@huawei.com, catalin.marinas@arm.com, realean2@ie.ibm.com On Thu 30 Nov 2017, 15:49, Michal Hocko wrote: > On Thu 23-11-17 11:14:52, Andrea Reale wrote: > > Adding a "remove" sysfs handle that can be used to trigger > > memory hotremove manually, exactly simmetrically with > > what happens with the "probe" device for hot-add. > > > > This is usueful for architecture that do not rely on > > ACPI for memory hot-remove. > > As already said elsewhere, this really has to check the online status of > the range and fail some is still online. > This is actually still done in remove_memory() (patch 2/5) with walk_memory_range. We just return an error rather than BUGing(). Or are you referring to something else? > > Signed-off-by: Andrea Reale > > Signed-off-by: Maciej Bielski > > --- > > drivers/base/memory.c | 34 +++++++++++++++++++++++++++++++++- > > 1 file changed, 33 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/base/memory.c b/drivers/base/memory.c > > index 1d60b58..8ccb67c 100644 > > --- a/drivers/base/memory.c > > +++ b/drivers/base/memory.c > > @@ -530,7 +530,36 @@ memory_probe_store(struct device *dev, struct device_attribute *attr, > > } > > > > static DEVICE_ATTR(probe, S_IWUSR, NULL, memory_probe_store); > > -#endif > > + > > +#ifdef CONFIG_MEMORY_HOTREMOVE > > +static ssize_t > > +memory_remove_store(struct device *dev, > > + struct device_attribute *attr, const char *buf, size_t count) > > +{ > > + u64 phys_addr; > > + int nid, ret; > > + unsigned long pages_per_block = PAGES_PER_SECTION * sections_per_block; > > + > > + ret = kstrtoull(buf, 0, &phys_addr); > > + if (ret) > > + return ret; > > + > > + if (phys_addr & ((pages_per_block << PAGE_SHIFT) - 1)) > > + return -EINVAL; > > + > > + nid = memory_add_physaddr_to_nid(phys_addr); > > + ret = lock_device_hotplug_sysfs(); > > + if (ret) > > + return ret; > > + > > + remove_memory(nid, phys_addr, > > + MIN_MEMORY_BLOCK_SIZE * sections_per_block); > > + unlock_device_hotplug(); > > + return count; > > +} > > +static DEVICE_ATTR(remove, S_IWUSR, NULL, memory_remove_store); > > +#endif /* CONFIG_MEMORY_HOTREMOVE */ > > +#endif /* CONFIG_ARCH_MEMORY_PROBE */ > > > > #ifdef CONFIG_MEMORY_FAILURE > > /* > > @@ -790,6 +819,9 @@ bool is_memblock_offlined(struct memory_block *mem) > > static struct attribute *memory_root_attrs[] = { > > #ifdef CONFIG_ARCH_MEMORY_PROBE > > &dev_attr_probe.attr, > > +#ifdef CONFIG_MEMORY_HOTREMOVE > > + &dev_attr_remove.attr, > > +#endif > > #endif > > > > #ifdef CONFIG_MEMORY_FAILURE > > -- > > 2.7.4 Thanks, Andrea > > -- > Michal Hocko > SUSE Labs > -- 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