From: Konrad Rzeszutek Wilk <konrad@darnok.org>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: linux-mm@kvack.org, kamezawa.hiroyu@jp.fujitsu.com,
dhillf@gmail.com, rientjes@google.com, mhocko@suse.cz,
akpm@linux-foundation.org, hannes@cmpxchg.org,
linux-kernel@vger.kernel.org, cgroups@vger.kernel.org
Subject: Re: [PATCH -V8 02/16] hugetlb: don't use ERR_PTR with VM_FAULT* values
Date: Sat, 9 Jun 2012 07:10:11 -0400 [thread overview]
Message-ID: <20120609111010.GA16034@localhost.localdomain> (raw)
In-Reply-To: <1339232401-14392-3-git-send-email-aneesh.kumar@linux.vnet.ibm.com>
On Sat, Jun 09, 2012 at 02:29:47PM +0530, Aneesh Kumar K.V wrote:
> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>
> The current use of VM_FAULT_* codes with ERR_PTR requires us to ensure
> VM_FAULT_* values will not exceed MAX_ERRNO value. Decouple the
> VM_FAULT_* values from MAX_ERRNO.
I see you using the -ENOMEM|-ENOSPC, but I don't see any reference in the
code to MAX_ERRNO? Can you provide a comment explaining in a tad little
bit about the interaction of MAX_ERRNO and VM_FAULT?
>
> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
> mm/hugetlb.c | 18 +++++++++++++-----
> 1 file changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index c868309..34a7e23 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1123,10 +1123,10 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
> */
> chg = vma_needs_reservation(h, vma, addr);
> if (chg < 0)
> - return ERR_PTR(-VM_FAULT_OOM);
> + return ERR_PTR(-ENOMEM);
> if (chg)
> if (hugepage_subpool_get_pages(spool, chg))
> - return ERR_PTR(-VM_FAULT_SIGBUS);
> + return ERR_PTR(-ENOSPC);
>
> spin_lock(&hugetlb_lock);
> page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve);
> @@ -1136,7 +1136,7 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
> page = alloc_buddy_huge_page(h, NUMA_NO_NODE);
> if (!page) {
> hugepage_subpool_put_pages(spool, chg);
> - return ERR_PTR(-VM_FAULT_SIGBUS);
> + return ERR_PTR(-ENOSPC);
> }
> }
>
> @@ -2496,6 +2496,7 @@ retry_avoidcopy:
> new_page = alloc_huge_page(vma, address, outside_reserve);
>
> if (IS_ERR(new_page)) {
> + long err = PTR_ERR(new_page);
> page_cache_release(old_page);
>
> /*
> @@ -2524,7 +2525,10 @@ retry_avoidcopy:
>
> /* Caller expects lock to be held */
> spin_lock(&mm->page_table_lock);
> - return -PTR_ERR(new_page);
> + if (err == -ENOMEM)
> + return VM_FAULT_OOM;
> + else
> + return VM_FAULT_SIGBUS;
> }
>
> /*
> @@ -2642,7 +2646,11 @@ retry:
> goto out;
> page = alloc_huge_page(vma, address, 0);
> if (IS_ERR(page)) {
> - ret = -PTR_ERR(page);
> + ret = PTR_ERR(page);
> + if (ret == -ENOMEM)
> + ret = VM_FAULT_OOM;
> + else
> + ret = VM_FAULT_SIGBUS;
> goto out;
> }
> clear_huge_page(page, address, pages_per_huge_page(h));
> --
> 1.7.10
>
> --
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next prev parent reply other threads:[~2012-06-09 11:10 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-09 8:59 [PATCH -V8 00/16] hugetlb: Add HugeTLB controller to control HugeTLB allocation Aneesh Kumar K.V
2012-06-09 8:59 ` [PATCH -V8 01/16] hugetlb: rename max_hstate to hugetlb_max_hstate Aneesh Kumar K.V
2012-06-09 8:59 ` [PATCH -V8 02/16] hugetlb: don't use ERR_PTR with VM_FAULT* values Aneesh Kumar K.V
2012-06-09 11:10 ` Konrad Rzeszutek Wilk [this message]
2012-06-09 13:17 ` Aneesh Kumar K.V
2012-06-09 19:28 ` KOSAKI Motohiro
2012-06-10 1:59 ` Hillf Danton
2012-06-09 8:59 ` [PATCH -V8 03/16] hugetlb: add an inline helper for finding hstate index Aneesh Kumar K.V
2012-06-09 8:59 ` [PATCH -V8 04/16] hugetlb: use mmu_gather instead of a temporary linked list for accumulating pages Aneesh Kumar K.V
2012-06-09 8:59 ` [PATCH -V8 05/16] hugetlb: avoid taking i_mmap_mutex in unmap_single_vma() for hugetlb Aneesh Kumar K.V
2012-06-09 9:44 ` Johannes Weiner
2012-06-09 13:03 ` Aneesh Kumar K.V
2012-06-09 14:49 ` Johannes Weiner
2012-06-09 8:59 ` [PATCH -V8 06/16] hugetlb: simplify migrate_huge_page() Aneesh Kumar K.V
2012-06-12 7:31 ` Kamezawa Hiroyuki
2012-06-09 8:59 ` [PATCH -V8 07/16] hugetlb: add a list for tracking in-use HugeTLB pages Aneesh Kumar K.V
2012-06-09 8:59 ` [PATCH -V8 08/16] hugetlb: Make some static variables global Aneesh Kumar K.V
2012-06-12 7:35 ` Kamezawa Hiroyuki
2012-06-09 8:59 ` [PATCH -V8 09/16] mm/hugetlb: Add new HugeTLB cgroup Aneesh Kumar K.V
2012-06-12 7:46 ` Kamezawa Hiroyuki
2012-06-12 9:37 ` Aneesh Kumar K.V
2012-06-09 8:59 ` [PATCH -V8 10/16] hugetlb/cgroup: Add the cgroup pointer to page lru Aneesh Kumar K.V
2012-06-09 11:14 ` Konrad Rzeszutek Wilk
2012-06-09 17:04 ` Aneesh Kumar K.V
2012-06-11 8:16 ` Michal Hocko
2012-06-11 9:03 ` Aneesh Kumar K.V
2012-06-11 9:16 ` Michal Hocko
2012-06-11 9:33 ` Aneesh Kumar K.V
2012-06-11 8:41 ` Kamezawa Hiroyuki
2012-06-12 7:52 ` Kamezawa Hiroyuki
2012-06-12 9:40 ` Aneesh Kumar K.V
2012-06-09 8:59 ` [PATCH -V8 11/16] hugetlb/cgroup: Add charge/uncharge routines for hugetlb cgroup Aneesh Kumar K.V
2012-06-11 8:38 ` Michal Hocko
2012-06-11 9:10 ` Michal Hocko
2012-06-11 9:28 ` Aneesh Kumar K.V
2012-06-11 12:59 ` Michal Hocko
2012-06-11 15:35 ` Aneesh Kumar K.V
2012-06-12 8:08 ` Kamezawa Hiroyuki
2012-06-12 10:50 ` Aneesh Kumar K.V
2012-06-13 11:02 ` Kamezawa Hiroyuki
2012-06-09 8:59 ` [PATCH -V8 12/16] hugetlb/cgroup: Add support for cgroup removal Aneesh Kumar K.V
2012-06-11 8:52 ` Michal Hocko
2012-06-11 9:40 ` Aneesh Kumar K.V
2012-06-11 13:14 ` Michal Hocko
2012-06-11 15:34 ` Aneesh Kumar K.V
2012-06-12 8:23 ` Kamezawa Hiroyuki
2012-06-12 10:52 ` Aneesh Kumar K.V
2012-06-09 8:59 ` [PATCH -V8 13/16] hugetlb/cgroup: add hugetlb cgroup control files Aneesh Kumar K.V
2012-06-09 11:19 ` Konrad Rzeszutek Wilk
2012-06-11 9:02 ` Michal Hocko
2012-06-11 9:43 ` Aneesh Kumar K.V
2012-06-11 13:15 ` Michal Hocko
2012-06-12 8:35 ` Kamezawa Hiroyuki
2012-06-12 10:58 ` Aneesh Kumar K.V
2012-06-13 0:16 ` Kamezawa Hiroyuki
2012-06-09 8:59 ` [PATCH -V8 14/16] hugetlb/cgroup: add charge/uncharge calls for HugeTLB alloc/free Aneesh Kumar K.V
2012-06-09 9:23 ` Johannes Weiner
2012-06-09 13:09 ` Aneesh Kumar K.V
2012-06-09 14:30 ` Johannes Weiner
2012-06-09 15:55 ` Aneesh Kumar K.V
2012-06-11 9:19 ` Michal Hocko
2012-06-11 9:21 ` Michal Hocko
2012-06-11 10:29 ` Aneesh Kumar K.V
2012-06-09 9:00 ` [PATCH -V8 15/16] hugetlb/cgroup: migrate hugetlb cgroup info from oldpage to new page during migration Aneesh Kumar K.V
2012-06-11 9:24 ` Michal Hocko
2012-06-11 10:17 ` Aneesh Kumar K.V
2012-06-12 8:51 ` Kamezawa Hiroyuki
2012-06-12 11:00 ` Aneesh Kumar K.V
2012-06-13 11:15 ` Kamezawa Hiroyuki
2012-06-09 9:00 ` [PATCH -V8 16/16] hugetlb/cgroup: add HugeTLB controller documentation Aneesh Kumar K.V
2012-06-12 8:57 ` Kamezawa Hiroyuki
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