Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757013AbaGBVZu (ORCPT ); Wed, 2 Jul 2014 17:25:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38149 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755868AbaGBVZs (ORCPT ); Wed, 2 Jul 2014 17:25:48 -0400 Date: Wed, 2 Jul 2014 17:25:29 -0400 From: Luiz Capitulino To: David Rientjes 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 Message-ID: <20140702172529.347f2dd2@redhat.com> In-Reply-To: References: Organization: Red Hat MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 30 Jun 2014 16:57:06 -0700 (PDT) David Rientjes wrote: > Three different interfaces alter the maximum number of hugepages for an > hstate: > > - /proc/sys/vm/nr_hugepages for global number of hugepages of the default > hstate, > > - /sys/kernel/mm/hugepages/hugepages-X/nr_hugepages for global number of > hugepages for a specific hstate, and > > - /sys/kernel/mm/hugepages/hugepages-X/nr_hugepages/mempolicy for number of > hugepages for a specific hstate over the set of allowed nodes. > > Generalize the code so that a single function handles all of these writes > instead of duplicating the code in two different functions. > > This decreases the number of lines of code, but also reduces the size of > .text by about half a percent since set_max_huge_pages() can be inlined. > > Signed-off-by: David Rientjes > --- > mm/hugetlb.c | 61 ++++++++++++++++++++++++++---------------------------------- > 1 file changed, 26 insertions(+), 35 deletions(-) > > 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. > - > - 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/