Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752390Ab3HUJ5u (ORCPT ); Wed, 21 Aug 2013 05:57:50 -0400 Received: from e28smtp02.in.ibm.com ([122.248.162.2]:48766 "EHLO e28smtp02.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751675Ab3HUJ5s (ORCPT ); Wed, 21 Aug 2013 05:57:48 -0400 From: "Aneesh Kumar K.V" To: Joonsoo Kim , Andrew Morton Cc: Rik van Riel , Mel Gorman , Michal Hocko , KAMEZAWA Hiroyuki , Hugh Dickins , Davidlohr Bueso , David Gibson , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Joonsoo Kim , Wanpeng Li , Naoya Horiguchi , Hillf Danton , Joonsoo Kim Subject: Re: [PATCH v2 07/20] mm, hugetlb: unify region structure handling In-Reply-To: <1376040398-11212-8-git-send-email-iamjoonsoo.kim@lge.com> References: <1376040398-11212-1-git-send-email-iamjoonsoo.kim@lge.com> <1376040398-11212-8-git-send-email-iamjoonsoo.kim@lge.com> User-Agent: Notmuch/0.15.2+167~g5306b2b (http://notmuchmail.org) Emacs/24.3.50.1 (x86_64-unknown-linux-gnu) Date: Wed, 21 Aug 2013 15:27:38 +0530 Message-ID: <87k3jfgyct.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13082109-5816-0000-0000-00000983DB4B Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6808 Lines: 200 Joonsoo Kim writes: > Currently, to track a reserved and allocated region, we use two different > ways for MAP_SHARED and MAP_PRIVATE. For MAP_SHARED, we use > address_mapping's private_list and, for MAP_PRIVATE, we use a resv_map. > Now, we are preparing to change a coarse grained lock which protect > a region structure to fine grained lock, and this difference hinder it. > So, before changing it, unify region structure handling. > > Signed-off-by: Joonsoo Kim As mentioned earlier kref_put is confusing because we always have reference count == 1 , otherwise Reviewed-by: Aneesh Kumar K.V > > diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c > index a3f868a..9bf2c4a 100644 > --- a/fs/hugetlbfs/inode.c > +++ b/fs/hugetlbfs/inode.c > @@ -366,7 +366,12 @@ static void truncate_hugepages(struct inode *inode, loff_t lstart) > > static void hugetlbfs_evict_inode(struct inode *inode) > { > + struct resv_map *resv_map; > + > truncate_hugepages(inode, 0); > + resv_map = (struct resv_map *)inode->i_mapping->private_data; > + if (resv_map) > + kref_put(&resv_map->refs, resv_map_release); > clear_inode(inode); > } > > @@ -468,6 +473,11 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb, > umode_t mode, dev_t dev) > { > struct inode *inode; > + struct resv_map *resv_map; > + > + resv_map = resv_map_alloc(); > + if (!resv_map) > + return NULL; > > inode = new_inode(sb); > if (inode) { > @@ -477,7 +487,7 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb, > inode->i_mapping->a_ops = &hugetlbfs_aops; > inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info; > inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; > - INIT_LIST_HEAD(&inode->i_mapping->private_list); > + inode->i_mapping->private_data = resv_map; > info = HUGETLBFS_I(inode); > /* > * The policy is initialized here even if we are creating a > @@ -507,7 +517,9 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb, > break; > } > lockdep_annotate_inode_mutex_key(inode); > - } > + } else > + kref_put(&resv_map->refs, resv_map_release); > + > return inode; > } > > diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h > index 6b4890f..2677c07 100644 > --- a/include/linux/hugetlb.h > +++ b/include/linux/hugetlb.h > @@ -5,6 +5,8 @@ > #include > #include > #include > +#include > +#include > > struct ctl_table; > struct user_struct; > @@ -22,6 +24,13 @@ struct hugepage_subpool { > long max_hpages, used_hpages; > }; > > +struct resv_map { > + struct kref refs; > + struct list_head regions; > +}; > +extern struct resv_map *resv_map_alloc(void); > +void resv_map_release(struct kref *ref); > + > extern spinlock_t hugetlb_lock; > extern int hugetlb_max_hstate __read_mostly; > #define for_each_hstate(h) \ > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 3f834f1..8751e2c 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -375,12 +375,7 @@ static void set_vma_private_data(struct vm_area_struct *vma, > vma->vm_private_data = (void *)value; > } > > -struct resv_map { > - struct kref refs; > - struct list_head regions; > -}; > - > -static struct resv_map *resv_map_alloc(void) > +struct resv_map *resv_map_alloc(void) > { > struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); > if (!resv_map) > @@ -392,7 +387,7 @@ static struct resv_map *resv_map_alloc(void) > return resv_map; > } > > -static void resv_map_release(struct kref *ref) > +void resv_map_release(struct kref *ref) > { > struct resv_map *resv_map = container_of(ref, struct resv_map, refs); > > @@ -1092,8 +1087,9 @@ static long vma_needs_reservation(struct hstate *h, > > if (vma->vm_flags & VM_MAYSHARE) { > pgoff_t idx = vma_hugecache_offset(h, vma, addr); > - return region_chg(&inode->i_mapping->private_list, > - idx, idx + 1); > + struct resv_map *resv = inode->i_mapping->private_data; > + > + return region_chg(&resv->regions, idx, idx + 1); > > } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { > return 1; > @@ -1117,7 +1113,9 @@ static void vma_commit_reservation(struct hstate *h, > > if (vma->vm_flags & VM_MAYSHARE) { > pgoff_t idx = vma_hugecache_offset(h, vma, addr); > - region_add(&inode->i_mapping->private_list, idx, idx + 1); > + struct resv_map *resv = inode->i_mapping->private_data; > + > + region_add(&resv->regions, idx, idx + 1); > > } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { > pgoff_t idx = vma_hugecache_offset(h, vma, addr); > @@ -3074,6 +3072,7 @@ int hugetlb_reserve_pages(struct inode *inode, > long ret, chg; > struct hstate *h = hstate_inode(inode); > struct hugepage_subpool *spool = subpool_inode(inode); > + struct resv_map *resv_map; > > /* > * Only apply hugepage reservation if asked. At fault time, an > @@ -3089,10 +3088,13 @@ int hugetlb_reserve_pages(struct inode *inode, > * to reserve the full area even if read-only as mprotect() may be > * called to make the mapping read-write. Assume !vma is a shm mapping > */ > - if (!vma || vma->vm_flags & VM_MAYSHARE) > - chg = region_chg(&inode->i_mapping->private_list, from, to); > - else { > - struct resv_map *resv_map = resv_map_alloc(); > + if (!vma || vma->vm_flags & VM_MAYSHARE) { > + resv_map = inode->i_mapping->private_data; > + > + chg = region_chg(&resv_map->regions, from, to); > + > + } else { > + resv_map = resv_map_alloc(); > if (!resv_map) > return -ENOMEM; > > @@ -3135,7 +3137,7 @@ int hugetlb_reserve_pages(struct inode *inode, > * else has to be done for private mappings here > */ > if (!vma || vma->vm_flags & VM_MAYSHARE) > - region_add(&inode->i_mapping->private_list, from, to); > + region_add(&resv_map->regions, from, to); > return 0; > out_err: > if (vma) > @@ -3146,9 +3148,12 @@ out_err: > void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) > { > struct hstate *h = hstate_inode(inode); > - long chg = region_truncate(&inode->i_mapping->private_list, offset); > + struct resv_map *resv_map = inode->i_mapping->private_data; > + long chg = 0; > struct hugepage_subpool *spool = subpool_inode(inode); > > + if (resv_map) > + chg = region_truncate(&resv_map->regions, offset); > spin_lock(&inode->i_lock); > inode->i_blocks -= (blocks_per_huge_page(h) * freed); > spin_unlock(&inode->i_lock); > -- > 1.7.9.5 -- 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/