Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965067AbbLQWqS (ORCPT ); Thu, 17 Dec 2015 17:46:18 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:38277 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932946AbbLQWqQ (ORCPT ); Thu, 17 Dec 2015 17:46:16 -0500 Subject: Re: [PATCH 1/8] hugetlb: make mm and fs code explicitly non-modular To: Paul Gortmaker , linux-kernel@vger.kernel.org References: <1450379466-23115-1-git-send-email-paul.gortmaker@windriver.com> <1450379466-23115-2-git-send-email-paul.gortmaker@windriver.com> Cc: Nadia Yvette Chambers , Alexander Viro , Andrew Morton , Naoya Horiguchi , David Rientjes , Hillf Danton , Davidlohr Bueso , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org From: Mike Kravetz Message-ID: <56733B25.6090506@oracle.com> Date: Thu, 17 Dec 2015 14:45:57 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <1450379466-23115-2-git-send-email-paul.gortmaker@windriver.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Source-IP: aserv0022.oracle.com [141.146.126.234] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6026 Lines: 194 On 12/17/2015 11:10 AM, Paul Gortmaker wrote: > The Kconfig currently controlling compilation of this code is: > > config HUGETLBFS > bool "HugeTLB file system support" > > ...meaning that it currently is not being built as a module by anyone. > > Lets remove the modular code that is essentially orphaned, so that > when reading the driver there is no doubt it is builtin-only. > > Since module_init translates to device_initcall in the non-modular > case, the init ordering gets moved to earlier levels when we use the > more appropriate initcalls here. > > Originally I had the fs part and the mm part as separate commits, > just by happenstance of the nature of how I detected these > non-modular use cases. But that can possibly introduce regressions > if the patch merge ordering puts the fs part 1st -- as the 0-day > testing reported a splat at mount time. > > Investigating with "initcall_debug" showed that the delta was > init_hugetlbfs_fs being called _before_ hugetlb_init instead of > after. So both the fs change and the mm change are here together. > > In addition, it worked before due to luck of link order, since they > were both in the same initcall category. So we now have the fs > part using fs_initcall, and the mm part using subsys_initcall, > which puts it one bucket earlier. It now passes the basic sanity > test that failed in earlier 0-day testing. > > We delete the MODULE_LICENSE tag and capture that information at the > top of the file alongside author comments, etc. > > We don't replace module.h with init.h since the file already has that. > Also note that MODULE_ALIAS is a no-op for non-modular code. > > Cc: Nadia Yvette Chambers > Cc: Alexander Viro > Cc: Andrew Morton > Cc: Naoya Horiguchi > Cc: Mike Kravetz > Cc: David Rientjes > Cc: Hillf Danton > Cc: Davidlohr Bueso > Cc: linux-mm@kvack.org > Cc: linux-fsdevel@vger.kernel.org > Reported-by: kernel test robot > Signed-off-by: Paul Gortmaker > --- > fs/hugetlbfs/inode.c | 27 ++------------------------- > mm/hugetlb.c | 39 +-------------------------------------- > 2 files changed, 3 insertions(+), 63 deletions(-) > > diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c > index de4bdfac0cec..dd04c2ad23b3 100644 > --- a/fs/hugetlbfs/inode.c > +++ b/fs/hugetlbfs/inode.c > @@ -4,11 +4,11 @@ > * Nadia Yvette Chambers, 2002 > * > * Copyright (C) 2002 Linus Torvalds. > + * License: GPL > */ > > #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > > -#include > #include > #include > #include /* remove ASAP */ > @@ -1201,7 +1201,6 @@ static struct file_system_type hugetlbfs_fs_type = { > .mount = hugetlbfs_mount, > .kill_sb = kill_litter_super, > }; > -MODULE_ALIAS_FS("hugetlbfs"); > > static struct vfsmount *hugetlbfs_vfsmount[HUGE_MAX_HSTATE]; > > @@ -1355,26 +1354,4 @@ static int __init init_hugetlbfs_fs(void) > out2: > return error; > } > - > -static void __exit exit_hugetlbfs_fs(void) > -{ > - struct hstate *h; > - int i; > - > - > - /* > - * Make sure all delayed rcu free inodes are flushed before we > - * destroy cache. > - */ > - rcu_barrier(); > - kmem_cache_destroy(hugetlbfs_inode_cachep); > - i = 0; > - for_each_hstate(h) > - kern_unmount(hugetlbfs_vfsmount[i++]); > - unregister_filesystem(&hugetlbfs_fs_type); > -} > - > -module_init(init_hugetlbfs_fs) > -module_exit(exit_hugetlbfs_fs) > - > -MODULE_LICENSE("GPL"); > +fs_initcall(init_hugetlbfs_fs) > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index ef6963b577fd..be934df69b85 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -4,7 +4,6 @@ > */ > #include > #include > -#include > #include > #include > #include > @@ -2549,25 +2548,6 @@ static void hugetlb_unregister_node(struct node *node) > nhs->hugepages_kobj = NULL; > } > > -/* > - * hugetlb module exit: unregister hstate attributes from node devices > - * that have them. > - */ > -static void hugetlb_unregister_all_nodes(void) > -{ > - int nid; > - > - /* > - * disable node device registrations. > - */ > - register_hugetlbfs_with_node(NULL, NULL); > - > - /* > - * remove hstate attributes from any nodes that have them. > - */ > - for (nid = 0; nid < nr_node_ids; nid++) > - hugetlb_unregister_node(node_devices[nid]); > -} > > /* > * Register hstate attributes for a single node device. > @@ -2632,27 +2612,10 @@ static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) > return NULL; > } > > -static void hugetlb_unregister_all_nodes(void) { } > - > static void hugetlb_register_all_nodes(void) { } > > #endif > > -static void __exit hugetlb_exit(void) > -{ > - struct hstate *h; > - > - hugetlb_unregister_all_nodes(); > - > - for_each_hstate(h) { > - kobject_put(hstate_kobjs[hstate_index(h)]); > - } > - > - kobject_put(hugepages_kobj); > - kfree(hugetlb_fault_mutex_table); > -} > -module_exit(hugetlb_exit); > - > static int __init hugetlb_init(void) > { > int i; > @@ -2690,7 +2653,7 @@ static int __init hugetlb_init(void) > mutex_init(&hugetlb_fault_mutex_table[i]); > return 0; > } > -module_init(hugetlb_init); > +subsys_initcall(hugetlb_init); > > /* Should be called on processing a hugepagesz=... option */ > void __init hugetlb_add_hstate(unsigned int order) > I like the removal of code. Reviewed-By: Mike Kravetz -- Mike Kravetz -- 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/