diff mbox series

[RESEND,v2] mm,hugetlb: remove mlock ulimit for SHM_HUGETLB

Message ID 20211008195725.33083-1-zhangyiru3@huawei.com (mailing list archive)
State New
Headers show
Series [RESEND,v2] mm,hugetlb: remove mlock ulimit for SHM_HUGETLB | expand

Commit Message

zhangyiru Oct. 8, 2021, 7:57 p.m. UTC
commit 21a3c273f88c9cbbaf7e ("mm, hugetlb: add thread name and pid to
SHM_HUGETLB mlock rlimit warning") marked this as deprecated in 2012,
but it is not deleted yet.

Mike says he still see that message in log files on occasion,
so maybe we should preserve this warning.

Signed-off-by: zhangyiru <zhangyiru3@huawei.com>
---
Changelog:
 v2: preserve warning message
 v1: remove mlock ulimit for SHM_HUGETLB
---
 fs/hugetlbfs/inode.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

Comments

Mike Kravetz Oct. 8, 2021, 9:26 p.m. UTC | #1
On 10/8/21 12:57 PM, zhangyiru wrote:
> commit 21a3c273f88c9cbbaf7e ("mm, hugetlb: add thread name and pid to
> SHM_HUGETLB mlock rlimit warning") marked this as deprecated in 2012,
> but it is not deleted yet.
> 
> Mike says he still see that message in log files on occasion,
> so maybe we should preserve this warning.
> 
> Signed-off-by: zhangyiru <zhangyiru3@huawei.com>
> ---
> Changelog:
>  v2: preserve warning message
>  v1: remove mlock ulimit for SHM_HUGETLB
> ---
>  fs/hugetlbfs/inode.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
> index cdfb1ae78a3f..877d0ce9526c 100644
> --- a/fs/hugetlbfs/inode.c
> +++ b/fs/hugetlbfs/inode.c
> @@ -1470,10 +1470,9 @@ struct file *hugetlb_file_setup(const char *name, size_t size,
>  			pr_warn_once("%s (%d): Using mlock ulimits for SHM_HUGETLB is deprecated\n",
>  				current->comm, current->pid);
>  			task_unlock(current);
> -		} else {
> -			*ucounts = NULL;
> -			return ERR_PTR(-EPERM);
>  		}
> +		*ucounts = NULL;
> +		return ERR_PTR(-EPERM);

IIUC, deprecated means that use of the feature is discouraged but
technically still available.  With this patch, we use the term
deprecated and also remove the functionality.  Perhaps change the
warning to be the following?

pr_warn_once("%s (%d): Using mlock ulimits for SHM_HUGETLB is now obsolete\n",

Leaving the 'deprecated' message and removing the functionality may
confuse people if their application breaks after this patch.
Michal Hocko Oct. 11, 2021, 8:28 a.m. UTC | #2
On Fri 08-10-21 14:26:48, Mike Kravetz wrote:
> On 10/8/21 12:57 PM, zhangyiru wrote:
> > commit 21a3c273f88c9cbbaf7e ("mm, hugetlb: add thread name and pid to
> > SHM_HUGETLB mlock rlimit warning") marked this as deprecated in 2012,
> > but it is not deleted yet.
> > 
> > Mike says he still see that message in log files on occasion,
> > so maybe we should preserve this warning.
> > 
> > Signed-off-by: zhangyiru <zhangyiru3@huawei.com>
> > ---
> > Changelog:
> >  v2: preserve warning message
> >  v1: remove mlock ulimit for SHM_HUGETLB
> > ---
> >  fs/hugetlbfs/inode.c | 5 ++---
> >  1 file changed, 2 insertions(+), 3 deletions(-)
> > 
> > diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
> > index cdfb1ae78a3f..877d0ce9526c 100644
> > --- a/fs/hugetlbfs/inode.c
> > +++ b/fs/hugetlbfs/inode.c
> > @@ -1470,10 +1470,9 @@ struct file *hugetlb_file_setup(const char *name, size_t size,
> >  			pr_warn_once("%s (%d): Using mlock ulimits for SHM_HUGETLB is deprecated\n",
> >  				current->comm, current->pid);
> >  			task_unlock(current);
> > -		} else {
> > -			*ucounts = NULL;
> > -			return ERR_PTR(-EPERM);
> >  		}
> > +		*ucounts = NULL;
> > +		return ERR_PTR(-EPERM);
> 
> IIUC, deprecated means that use of the feature is discouraged but
> technically still available.  With this patch, we use the term
> deprecated and also remove the functionality.  Perhaps change the
> warning to be the following?
> 
> pr_warn_once("%s (%d): Using mlock ulimits for SHM_HUGETLB is now obsolete\n",

Agreed. I would even go with an addition "Please report if you have a
usecase for this functionality."

> Leaving the 'deprecated' message and removing the functionality may
> confuse people if their application breaks after this patch.
> -- 
> Mike Kravetz
diff mbox series

Patch

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index cdfb1ae78a3f..877d0ce9526c 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -1470,10 +1470,9 @@  struct file *hugetlb_file_setup(const char *name, size_t size,
 			pr_warn_once("%s (%d): Using mlock ulimits for SHM_HUGETLB is deprecated\n",
 				current->comm, current->pid);
 			task_unlock(current);
-		} else {
-			*ucounts = NULL;
-			return ERR_PTR(-EPERM);
 		}
+		*ucounts = NULL;
+		return ERR_PTR(-EPERM);
 	}
 
 	file = ERR_PTR(-ENOSPC);