Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753368AbaGCAou (ORCPT ); Wed, 2 Jul 2014 20:44:50 -0400 Received: from mail-ie0-f174.google.com ([209.85.223.174]:44447 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750809AbaGCAos (ORCPT ); Wed, 2 Jul 2014 20:44:48 -0400 Date: Wed, 2 Jul 2014 17:44:46 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Luiz Capitulino cc: Andrew Morton , Joonsoo Kim , Naoya Horiguchi , "Kirill A. Shutemov" , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [patch] mm, hugetlb: generalize writes to nr_hugepages In-Reply-To: <20140702172529.347f2dd2@redhat.com> Message-ID: References: <20140702172529.347f2dd2@redhat.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2 Jul 2014, Luiz Capitulino wrote: > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > > --- a/mm/hugetlb.c > > +++ b/mm/hugetlb.c > > @@ -1734,21 +1734,13 @@ static ssize_t nr_hugepages_show_common(struct kobject *kobj, > > return sprintf(buf, "%lu\n", nr_huge_pages); > > } > > > > -static ssize_t nr_hugepages_store_common(bool obey_mempolicy, > > - struct kobject *kobj, struct kobj_attribute *attr, > > - const char *buf, size_t len) > > +static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, > > + struct hstate *h, int nid, > > + unsigned long count, size_t len) > > { > > int err; > > - int nid; > > - unsigned long count; > > - struct hstate *h; > > NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY); > > > > - err = kstrtoul(buf, 10, &count); > > - if (err) > > - goto out; > > - > > - h = kobj_to_hstate(kobj, &nid); > > if (hstate_is_gigantic(h) && !gigantic_page_supported()) { > > err = -EINVAL; > > goto out; > > @@ -1784,6 +1776,23 @@ out: > > return err; > > } > > > > +static ssize_t nr_hugepages_store_common(bool obey_mempolicy, > > + struct kobject *kobj, const char *buf, > > + size_t len) > > +{ > > + struct hstate *h; > > + unsigned long count; > > + int nid; > > + int err; > > + > > + err = kstrtoul(buf, 10, &count); > > + if (err) > > + return err; > > + > > + h = kobj_to_hstate(kobj, &nid); > > + return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len); > > +} > > + > > static ssize_t nr_hugepages_show(struct kobject *kobj, > > struct kobj_attribute *attr, char *buf) > > { > > @@ -1793,7 +1802,7 @@ static ssize_t nr_hugepages_show(struct kobject *kobj, > > static ssize_t nr_hugepages_store(struct kobject *kobj, > > struct kobj_attribute *attr, const char *buf, size_t len) > > { > > - return nr_hugepages_store_common(false, kobj, attr, buf, len); > > + return nr_hugepages_store_common(false, kobj, buf, len); > > } > > HSTATE_ATTR(nr_hugepages); > > > > @@ -1812,7 +1821,7 @@ static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, > > static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, > > struct kobj_attribute *attr, const char *buf, size_t len) > > { > > - return nr_hugepages_store_common(true, kobj, attr, buf, len); > > + return nr_hugepages_store_common(true, kobj, buf, len); > > } > > HSTATE_ATTR(nr_hugepages_mempolicy); > > #endif > > @@ -2248,36 +2257,18 @@ static int hugetlb_sysctl_handler_common(bool obey_mempolicy, > > void __user *buffer, size_t *length, loff_t *ppos) > > { > > struct hstate *h = &default_hstate; > > - unsigned long tmp; > > + unsigned long tmp = h->max_huge_pages; > > int ret; > > > > - if (!hugepages_supported()) > > - return -ENOTSUPP; > > Shouldn't you add this check to __nr_hugepages_store_common()? Otherwise > looks good to me. > Hmm, I think you're right but I don't think __nr_hugepages_store_common() is the right place: if we have a legitimate hstate for the sysfs tunables then we should support hugepages. I think this should be kept in hugetlb_sysctl_handler_common(). > > - > > - tmp = h->max_huge_pages; > > - > > - if (write && hstate_is_gigantic(h) && !gigantic_page_supported()) > > - return -EINVAL; > > - > > table->data = &tmp; > > table->maxlen = sizeof(unsigned long); > > ret = proc_doulongvec_minmax(table, write, buffer, length, ppos); > > if (ret) > > goto out; > > > > - if (write) { > > - NODEMASK_ALLOC(nodemask_t, nodes_allowed, > > - GFP_KERNEL | __GFP_NORETRY); > > - if (!(obey_mempolicy && > > - init_nodemask_of_mempolicy(nodes_allowed))) { > > - NODEMASK_FREE(nodes_allowed); > > - nodes_allowed = &node_states[N_MEMORY]; > > - } > > - h->max_huge_pages = set_max_huge_pages(h, tmp, nodes_allowed); > > - > > - if (nodes_allowed != &node_states[N_MEMORY]) > > - NODEMASK_FREE(nodes_allowed); > > - } > > + if (write) > > + ret = __nr_hugepages_store_common(obey_mempolicy, h, > > + NUMA_NO_NODE, tmp, *length); > > out: > > return ret; > > } -- 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/