From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Rik van Riel <riel@redhat.com>, Mel Gorman <mgorman@suse.de>,
Michal Hocko <mhocko@suse.cz>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Hugh Dickins <hughd@google.com>,
Davidlohr Bueso <davidlohr.bueso@hp.com>,
David Gibson <david@gibson.dropbear.id.au>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Wanpeng Li <liwanp@linux.vnet.ibm.com>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
Hillf Danton <dhillf@gmail.com>
Subject: Re: [PATCH 06/18] mm, hugetlb: remove vma_need_reservation()
Date: Wed, 31 Jul 2013 13:56:30 +0900 [thread overview]
Message-ID: <20130731045630.GG2548@lge.com> (raw)
In-Reply-To: <87siywos3d.fsf@linux.vnet.ibm.com>
On Tue, Jul 30, 2013 at 11:19:58PM +0530, Aneesh Kumar K.V wrote:
> Joonsoo Kim <iamjoonsoo.kim@lge.com> writes:
>
> > vma_need_reservation() can be substituted by vma_has_reserves()
> > with minor change. These function do almost same thing,
> > so unifying them is better to maintain.
>
> I found the resulting code confusing and complex. I am sure there is
> more that what is explained in the commit message. If you are just doing
> this for cleanup, may be we should avoid doing this ?
I may need this cleanup, because I want to decide whether this page comes
from reserved page pool or not, more clearly. Without this, this decision
can be harder.
Anyway, I should describe the purpose of this patch in detail.
Thanks.
>
>
> >
> > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
> >
> > diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> > index bf2ee11..ff46a2c 100644
> > --- a/mm/hugetlb.c
> > +++ b/mm/hugetlb.c
> > @@ -451,8 +451,18 @@ void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
> > vma->vm_private_data = (void *)0;
> > }
> >
> > -/* Returns true if the VMA has associated reserve pages */
> > -static int vma_has_reserves(struct vm_area_struct *vma, long chg)
> > +/*
> > + * Determine if the huge page at addr within the vma has an associated
> > + * reservation. Where it does not we will need to logically increase
> > + * reservation and actually increase subpool usage before an allocation
> > + * can occur. Where any new reservation would be required the
> > + * reservation change is prepared, but not committed. Once the page
> > + * has been allocated from the subpool and instantiated the change should
> > + * be committed via vma_commit_reservation. No action is required on
> > + * failure.
> > + */
> > +static int vma_has_reserves(struct hstate *h,
> > + struct vm_area_struct *vma, unsigned long addr)
> > {
> > if (vma->vm_flags & VM_NORESERVE) {
> > /*
> > @@ -464,10 +474,22 @@ static int vma_has_reserves(struct vm_area_struct *vma, long chg)
> > * step. Currently, we don't have any other solution to deal
> > * with this situation properly, so add work-around here.
> > */
> > - if (vma->vm_flags & VM_MAYSHARE && chg == 0)
> > - return 1;
> > - else
> > - return 0;
> > + if (vma->vm_flags & VM_MAYSHARE) {
> > + struct address_space *mapping = vma->vm_file->f_mapping;
> > + struct inode *inode = mapping->host;
> > + pgoff_t idx = vma_hugecache_offset(h, vma, addr);
> > + struct resv_map *resv = inode->i_mapping->private_data;
> > + long chg;
> > +
> > + chg = region_chg(resv, idx, idx + 1);
> > + if (chg < 0)
> > + return -ENOMEM;
> > +
> > + if (chg == 0)
> > + return 1;
> > + }
> > +
> > + return 0;
> > }
> >
> > /* Shared mappings always use reserves */
> > @@ -478,8 +500,16 @@ static int vma_has_reserves(struct vm_area_struct *vma, long chg)
> > * Only the process that called mmap() has reserves for
> > * private mappings.
> > */
> > - if (is_vma_resv_set(vma, HPAGE_RESV_OWNER))
> > + if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
> > + pgoff_t idx = vma_hugecache_offset(h, vma, addr);
> > + struct resv_map *resv = vma_resv_map(vma);
> > +
> > + /* Just for allocating region structure */
> > + if (region_chg(resv, idx, idx + 1) < 0)
> > + return -ENOMEM;
> > +
> > return 1;
> > + }
> >
> > return 0;
> > }
> > @@ -542,8 +572,7 @@ static struct page *dequeue_huge_page_node(struct hstate *h, int nid)
> >
> > static struct page *dequeue_huge_page_vma(struct hstate *h,
> > struct vm_area_struct *vma,
> > - unsigned long address, int avoid_reserve,
> > - long chg)
> > + unsigned long address, int avoid_reserve)
> > {
> > struct page *page = NULL;
> > struct mempolicy *mpol;
> > @@ -558,7 +587,7 @@ static struct page *dequeue_huge_page_vma(struct hstate *h,
> > * have no page reserves. This check ensures that reservations are
> > * not "stolen". The child may still get SIGKILLed
> > */
> > - if (!vma_has_reserves(vma, chg) &&
> > + if (!vma_has_reserves(h, vma, address) &&
> > h->free_huge_pages - h->resv_huge_pages == 0)
> > return NULL;
> >
> > @@ -578,7 +607,7 @@ retry_cpuset:
> > if (page) {
> > if (avoid_reserve)
> > break;
> > - if (!vma_has_reserves(vma, chg))
> > + if (!vma_has_reserves(h, vma, address))
> > break;
> >
> > h->resv_huge_pages--;
> > @@ -1077,42 +1106,6 @@ static void return_unused_surplus_pages(struct hstate *h,
> > }
> > }
> >
> > -/*
> > - * Determine if the huge page at addr within the vma has an associated
> > - * reservation. Where it does not we will need to logically increase
> > - * reservation and actually increase subpool usage before an allocation
> > - * can occur. Where any new reservation would be required the
> > - * reservation change is prepared, but not committed. Once the page
> > - * has been allocated from the subpool and instantiated the change should
> > - * be committed via vma_commit_reservation. No action is required on
> > - * failure.
> > - */
> > -static long vma_needs_reservation(struct hstate *h,
> > - struct vm_area_struct *vma, unsigned long addr)
> > -{
> > - struct address_space *mapping = vma->vm_file->f_mapping;
> > - struct inode *inode = mapping->host;
> > -
> > - if (vma->vm_flags & VM_MAYSHARE) {
> > - pgoff_t idx = vma_hugecache_offset(h, vma, addr);
> > - struct resv_map *resv = inode->i_mapping->private_data;
> > -
> > - return region_chg(resv, idx, idx + 1);
> > -
> > - } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
> > - return 1;
> > -
> > - } else {
> > - long err;
> > - pgoff_t idx = vma_hugecache_offset(h, vma, addr);
> > - struct resv_map *resv = vma_resv_map(vma);
> > -
> > - err = region_chg(resv, idx, idx + 1);
> > - if (err < 0)
> > - return err;
> > - return 0;
> > - }
> > -}
> > static void vma_commit_reservation(struct hstate *h,
> > struct vm_area_struct *vma, unsigned long addr)
> > {
> > @@ -1140,8 +1133,7 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
> > struct hugepage_subpool *spool = subpool_vma(vma);
> > struct hstate *h = hstate_vma(vma);
> > struct page *page;
> > - long chg;
> > - int ret, idx;
> > + int ret, idx, has_reserve;
> > struct hugetlb_cgroup *h_cg;
> >
> > idx = hstate_index(h);
> > @@ -1153,20 +1145,21 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
> > * need pages and subpool limit allocated allocated if no reserve
> > * mapping overlaps.
> > */
> > - chg = vma_needs_reservation(h, vma, addr);
> > - if (chg < 0)
> > + has_reserve = vma_has_reserves(h, vma, addr);
> > + if (has_reserve < 0)
> > return ERR_PTR(-ENOMEM);
> > - if (chg)
> > - if (hugepage_subpool_get_pages(spool, chg))
> > +
> > + if (!has_reserve && (hugepage_subpool_get_pages(spool, 1) < 0))
> > return ERR_PTR(-ENOSPC);
> >
> > ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg);
> > if (ret) {
> > - hugepage_subpool_put_pages(spool, chg);
> > + if (!has_reserve)
> > + hugepage_subpool_put_pages(spool, 1);
> > return ERR_PTR(-ENOSPC);
> > }
> > spin_lock(&hugetlb_lock);
> > - page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, chg);
> > + page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve);
> > if (!page) {
> > spin_unlock(&hugetlb_lock);
> > page = alloc_buddy_huge_page(h, NUMA_NO_NODE);
> > @@ -1174,7 +1167,8 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
> > hugetlb_cgroup_uncharge_cgroup(idx,
> > pages_per_huge_page(h),
> > h_cg);
> > - hugepage_subpool_put_pages(spool, chg);
> > + if (!has_reserve)
> > + hugepage_subpool_put_pages(spool, 1);
> > return ERR_PTR(-ENOSPC);
> > }
> > spin_lock(&hugetlb_lock);
> > @@ -2769,7 +2763,7 @@ retry:
> > * the spinlock.
> > */
> > if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED))
> > - if (vma_needs_reservation(h, vma, address) < 0) {
> > + if (vma_has_reserves(h, vma, address) < 0) {
> > ret = VM_FAULT_OOM;
> > goto backout_unlocked;
> > }
> > @@ -2860,7 +2854,7 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
> > * consumed.
> > */
> > if ((flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) {
> > - if (vma_needs_reservation(h, vma, address) < 0) {
> > + if (vma_has_reserves(h, vma, address) < 0) {
> > ret = VM_FAULT_OOM;
> > goto out_mutex;
> > }
> > --
> > 1.7.9.5
>
> --
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next prev parent reply other threads:[~2013-07-31 4:56 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-29 5:31 [PATCH 00/18] mm, hugetlb: remove a hugetlb_instantiation_mutex Joonsoo Kim
2013-07-29 5:31 ` [PATCH 01/18] mm, hugetlb: protect reserved pages when softofflining requests the pages Joonsoo Kim
2013-07-29 7:24 ` Hillf Danton
2013-07-31 2:27 ` Joonsoo Kim
2013-07-31 2:49 ` Hillf Danton
2013-07-31 4:41 ` Joonsoo Kim
2013-07-31 6:21 ` Hillf Danton
2013-07-31 6:37 ` Joonsoo Kim
2013-07-31 15:25 ` Hillf Danton
2013-08-01 6:07 ` Joonsoo Kim
2013-08-01 16:17 ` Aneesh Kumar K.V
2013-08-04 5:10 ` Hillf Danton
2013-08-05 5:17 ` Aneesh Kumar K.V
2013-07-30 16:49 ` Aneesh Kumar K.V
2013-07-29 5:31 ` [PATCH 02/18] mm, hugetlb: change variable name reservations to resv Joonsoo Kim
2013-07-30 16:50 ` Aneesh Kumar K.V
2013-07-29 5:31 ` [PATCH 03/18] mm, hugetlb: unify region structure handling Joonsoo Kim
2013-07-30 17:27 ` Aneesh Kumar K.V
2013-07-31 2:36 ` Joonsoo Kim
2013-07-29 5:31 ` [PATCH 04/18] mm, hugetlb: region manipulation functions take resv_map rather list_head Joonsoo Kim
2013-07-29 5:31 ` [PATCH 05/18] mm, hugetlb: protect region tracking via newly introduced resv_map lock Joonsoo Kim
2013-07-29 8:58 ` Hillf Danton
2013-07-31 2:41 ` Joonsoo Kim
2013-07-29 18:53 ` Davidlohr Bueso
2013-07-31 2:43 ` Joonsoo Kim
2013-07-29 5:31 ` [PATCH 06/18] mm, hugetlb: remove vma_need_reservation() Joonsoo Kim
2013-07-29 17:52 ` Naoya Horiguchi
2013-07-31 4:53 ` Joonsoo Kim
2013-07-30 17:49 ` Aneesh Kumar K.V
2013-07-31 4:56 ` Joonsoo Kim [this message]
2013-07-29 5:31 ` [PATCH 07/18] mm, hugetlb: pass has_reserve to dequeue_huge_page_vma() Joonsoo Kim
2013-07-29 5:31 ` [PATCH 08/18] mm, hugetlb: do hugepage_subpool_get_pages() when avoid_reserve Joonsoo Kim
2013-07-29 18:05 ` Naoya Horiguchi
2013-07-31 5:02 ` Joonsoo Kim
2013-07-31 20:55 ` Naoya Horiguchi
2013-07-29 5:32 ` [PATCH 09/18] mm, hugetlb: unify has_reserve and avoid_reserve to use_reserve Joonsoo Kim
2013-07-29 5:32 ` [PATCH 10/18] mm, hugetlb: call vma_has_reserve() before entering alloc_huge_page() Joonsoo Kim
2013-07-29 18:27 ` Naoya Horiguchi
2013-07-31 5:06 ` Joonsoo Kim
2013-07-29 5:32 ` [PATCH 11/18] mm, hugetlb: move down outside_reserve check Joonsoo Kim
2013-07-29 18:39 ` Naoya Horiguchi
2013-07-31 5:08 ` Joonsoo Kim
2013-07-31 20:46 ` Naoya Horiguchi
2013-07-29 5:32 ` [PATCH 12/18] mm, hugetlb: remove a check for return value of alloc_huge_page() Joonsoo Kim
2013-07-29 5:32 ` [PATCH 13/18] mm, hugetlb: grab a page_table_lock after page_cache_release Joonsoo Kim
2013-07-29 18:50 ` Naoya Horiguchi
2013-07-29 5:32 ` [PATCH 14/18] mm, hugetlb: clean-up error handling in hugetlb_cow() Joonsoo Kim
2013-07-29 5:32 ` [PATCH 15/18] mm, hugetlb: move up anon_vma_prepare() Joonsoo Kim
2013-07-29 19:05 ` Naoya Horiguchi
2013-07-29 19:19 ` Naoya Horiguchi
2013-07-31 5:12 ` Joonsoo Kim
2013-07-31 16:43 ` Naoya Horiguchi
2013-07-29 5:32 ` [PATCH 16/18] mm, hugetlb: return a reserved page to a reserved pool if failed Joonsoo Kim
2013-07-29 20:19 ` Naoya Horiguchi
2013-07-31 5:21 ` Joonsoo Kim
2013-07-29 5:32 ` [PATCH 17/18] mm, hugetlb: retry if we fail to allocate a hugepage with use_reserve Joonsoo Kim
2013-07-29 7:28 ` David Gibson
2013-07-31 5:37 ` Joonsoo Kim
2013-08-03 10:43 ` David Gibson
2013-08-05 7:36 ` Joonsoo Kim
2013-08-07 0:18 ` Davidlohr Bueso
2013-08-07 1:03 ` David Gibson
2013-08-07 1:38 ` Davidlohr Bueso
2013-08-07 9:18 ` Joonsoo Kim
2013-08-09 0:02 ` David Gibson
2013-08-09 9:37 ` Joonsoo Kim
2013-07-29 5:32 ` [PATCH 18/18] mm, hugetlb: remove a hugetlb_instantiation_mutex Joonsoo Kim
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