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* [PATCH v3] alloc_tag: check mem_profiling_support in alloc_tag_init
@ 2025-05-12 19:42 Casey Chen
  2025-05-12 20:53 ` Suren Baghdasaryan
  0 siblings, 1 reply; 4+ messages in thread
From: Casey Chen @ 2025-05-12 19:42 UTC (permalink / raw)
  To: linux-mm; +Cc: surenb, kent.overstreet, yzhong, Casey Chen

If mem_profiling_support is false, for example by
sysctl.vm.mem_profiling=never, alloc_tag_init should skip
module tags allocation, codetag type registration and
procfs init.

Signed-off-by: Casey Chen <cachen@purestorage.com>
Reviewed-by: Yuanyuan Zhong <yzhong@purestorage.com>
---
 lib/alloc_tag.c | 34 +++++++++++++++++++---------------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
index 25ecc1334b67..7c798778669c 100644
--- a/lib/alloc_tag.c
+++ b/lib/alloc_tag.c
@@ -244,17 +244,6 @@ static void shutdown_mem_profiling(bool remove_file)
 	mem_profiling_support = false;
 }
 
-static void __init procfs_init(void)
-{
-	if (!mem_profiling_support)
-		return;
-
-	if (!proc_create_seq(ALLOCINFO_FILE_NAME, 0400, NULL, &allocinfo_seq_op)) {
-		pr_err("Failed to create %s file\n", ALLOCINFO_FILE_NAME);
-		shutdown_mem_profiling(false);
-	}
-}
-
 void __init alloc_tag_sec_init(void)
 {
 	struct alloc_tag *last_codetag;
@@ -762,19 +751,34 @@ static int __init alloc_tag_init(void)
 	};
 	int res;
 
+	sysctl_init();
+
+	if (!mem_profiling_support) {
+		pr_info("Memory allocation profiling is not supported!\n");
+		return 0;
+	}
+
+	if (!proc_create_seq(ALLOCINFO_FILE_NAME, 0400, NULL, &allocinfo_seq_op)) {
+		pr_err("Failed to create %s file\n", ALLOCINFO_FILE_NAME);
+		shutdown_mem_profiling(false);
+		return -EAGAIN;
+	}
+
 	res = alloc_mod_tags_mem();
-	if (res)
+	if (res) {
+		pr_err("Failed to allocate module tags\n");
+		shutdown_mem_profiling(true);
 		return res;
+	}
 
 	alloc_tag_cttype = codetag_register_type(&desc);
 	if (IS_ERR(alloc_tag_cttype)) {
+		pr_err("Failed to register codetag type with desc %s\n", desc.section);
 		free_mod_tags_mem();
+		shutdown_mem_profiling(true);
 		return PTR_ERR(alloc_tag_cttype);
 	}
 
-	sysctl_init();
-	procfs_init();
-
 	return 0;
 }
 module_init(alloc_tag_init);
-- 
2.49.0



^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v3] alloc_tag: check mem_profiling_support in alloc_tag_init
  2025-05-12 19:42 [PATCH v3] alloc_tag: check mem_profiling_support in alloc_tag_init Casey Chen
@ 2025-05-12 20:53 ` Suren Baghdasaryan
  2025-05-12 21:02   ` Casey Chen
  0 siblings, 1 reply; 4+ messages in thread
From: Suren Baghdasaryan @ 2025-05-12 20:53 UTC (permalink / raw)
  To: Casey Chen; +Cc: linux-mm, kent.overstreet, yzhong

On Mon, May 12, 2025 at 12:42 PM Casey Chen <cachen@purestorage.com> wrote:
>
> If mem_profiling_support is false, for example by
> sysctl.vm.mem_profiling=never, alloc_tag_init should skip
> module tags allocation, codetag type registration and
> procfs init.
>
> Signed-off-by: Casey Chen <cachen@purestorage.com>
> Reviewed-by: Yuanyuan Zhong <yzhong@purestorage.com>
> ---
>  lib/alloc_tag.c | 34 +++++++++++++++++++---------------
>  1 file changed, 19 insertions(+), 15 deletions(-)
>
> diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
> index 25ecc1334b67..7c798778669c 100644
> --- a/lib/alloc_tag.c
> +++ b/lib/alloc_tag.c
> @@ -244,17 +244,6 @@ static void shutdown_mem_profiling(bool remove_file)
>         mem_profiling_support = false;
>  }
>
> -static void __init procfs_init(void)
> -{
> -       if (!mem_profiling_support)
> -               return;
> -
> -       if (!proc_create_seq(ALLOCINFO_FILE_NAME, 0400, NULL, &allocinfo_seq_op)) {
> -               pr_err("Failed to create %s file\n", ALLOCINFO_FILE_NAME);
> -               shutdown_mem_profiling(false);
> -       }
> -}
> -
>  void __init alloc_tag_sec_init(void)
>  {
>         struct alloc_tag *last_codetag;
> @@ -762,19 +751,34 @@ static int __init alloc_tag_init(void)
>         };
>         int res;
>
> +       sysctl_init();
> +
> +       if (!mem_profiling_support) {
> +               pr_info("Memory allocation profiling is not supported!\n");
> +               return 0;
> +       }
> +
> +       if (!proc_create_seq(ALLOCINFO_FILE_NAME, 0400, NULL, &allocinfo_seq_op)) {

I suggest keeping file creation as the last step so that we don't have
to remove it if later steps fail.

> +               pr_err("Failed to create %s file\n", ALLOCINFO_FILE_NAME);
> +               shutdown_mem_profiling(false);
> +               return -EAGAIN;

Why EAGAIN? I would just let it fall through returning 0 (after moving
this to the end as I suggested in my previous comment).

> +       }
> +
>         res = alloc_mod_tags_mem();
> -       if (res)
> +       if (res) {
> +               pr_err("Failed to allocate module tags\n");

The error message is a bit misleading here since we are not allocating
module tags but reserving virtual space for them. Maybe:
"Failed to reserve address space for module tags"

> +               shutdown_mem_profiling(true);
>                 return res;
> +       }
>
>         alloc_tag_cttype = codetag_register_type(&desc);
>         if (IS_ERR(alloc_tag_cttype)) {
> +               pr_err("Failed to register codetag type with desc %s\n", desc.section);

pr_err("Allocation tags registration failed, errno = %d\n", ret);

>                 free_mod_tags_mem();
> +               shutdown_mem_profiling(true);
>                 return PTR_ERR(alloc_tag_cttype);
>         }
>
> -       sysctl_init();
> -       procfs_init();
> -
>         return 0;
>  }
>  module_init(alloc_tag_init);
> --
> 2.49.0
>


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v3] alloc_tag: check mem_profiling_support in alloc_tag_init
  2025-05-12 20:53 ` Suren Baghdasaryan
@ 2025-05-12 21:02   ` Casey Chen
  2025-05-13  2:06     ` Suren Baghdasaryan
  0 siblings, 1 reply; 4+ messages in thread
From: Casey Chen @ 2025-05-12 21:02 UTC (permalink / raw)
  To: Suren Baghdasaryan; +Cc: linux-mm, kent.overstreet, yzhong

On Mon, May 12, 2025 at 1:53 PM Suren Baghdasaryan <surenb@google.com> wrote:
>
> On Mon, May 12, 2025 at 12:42 PM Casey Chen <cachen@purestorage.com> wrote:
> >
> > If mem_profiling_support is false, for example by
> > sysctl.vm.mem_profiling=never, alloc_tag_init should skip
> > module tags allocation, codetag type registration and
> > procfs init.
> >
> > Signed-off-by: Casey Chen <cachen@purestorage.com>
> > Reviewed-by: Yuanyuan Zhong <yzhong@purestorage.com>
> > ---
> >  lib/alloc_tag.c | 34 +++++++++++++++++++---------------
> >  1 file changed, 19 insertions(+), 15 deletions(-)
> >
> > diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
> > index 25ecc1334b67..7c798778669c 100644
> > --- a/lib/alloc_tag.c
> > +++ b/lib/alloc_tag.c
> > @@ -244,17 +244,6 @@ static void shutdown_mem_profiling(bool remove_file)
> >         mem_profiling_support = false;
> >  }
> >
> > -static void __init procfs_init(void)
> > -{
> > -       if (!mem_profiling_support)
> > -               return;
> > -
> > -       if (!proc_create_seq(ALLOCINFO_FILE_NAME, 0400, NULL, &allocinfo_seq_op)) {
> > -               pr_err("Failed to create %s file\n", ALLOCINFO_FILE_NAME);
> > -               shutdown_mem_profiling(false);
> > -       }
> > -}
> > -
> >  void __init alloc_tag_sec_init(void)
> >  {
> >         struct alloc_tag *last_codetag;
> > @@ -762,19 +751,34 @@ static int __init alloc_tag_init(void)
> >         };
> >         int res;
> >
> > +       sysctl_init();
> > +
> > +       if (!mem_profiling_support) {
> > +               pr_info("Memory allocation profiling is not supported!\n");
> > +               return 0;
> > +       }
> > +
> > +       if (!proc_create_seq(ALLOCINFO_FILE_NAME, 0400, NULL, &allocinfo_seq_op)) {
>
> I suggest keeping file creation as the last step so that we don't have
> to remove it if later steps fail.
>

If the file creation is the last step, how could it clean up codetag
type registration ? As we miss codetag unregistration function, I
think codetag type registration should be the last step.

> > +               pr_err("Failed to create %s file\n", ALLOCINFO_FILE_NAME);
> > +               shutdown_mem_profiling(false);
> > +               return -EAGAIN;
>
> Why EAGAIN? I would just let it fall through returning 0 (after moving
> this to the end as I suggested in my previous comment).
>

return 0 is fine to me if this fails. EAGAIN sounds fine too.

> > +       }
> > +
> >         res = alloc_mod_tags_mem();
> > -       if (res)
> > +       if (res) {
> > +               pr_err("Failed to allocate module tags\n");
>
> The error message is a bit misleading here since we are not allocating
> module tags but reserving virtual space for them. Maybe:
> "Failed to reserve address space for module tags"
>

Sounds good!

> > +               shutdown_mem_profiling(true);
> >                 return res;
> > +       }
> >
> >         alloc_tag_cttype = codetag_register_type(&desc);
> >         if (IS_ERR(alloc_tag_cttype)) {
> > +               pr_err("Failed to register codetag type with desc %s\n", desc.section);
>
> pr_err("Allocation tags registration failed, errno = %d\n", ret);
>

Sounds good too.

> >                 free_mod_tags_mem();
> > +               shutdown_mem_profiling(true);
> >                 return PTR_ERR(alloc_tag_cttype);
> >         }
> >
> > -       sysctl_init();
> > -       procfs_init();
> > -
> >         return 0;
> >  }
> >  module_init(alloc_tag_init);
> > --
> > 2.49.0
> >


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v3] alloc_tag: check mem_profiling_support in alloc_tag_init
  2025-05-12 21:02   ` Casey Chen
@ 2025-05-13  2:06     ` Suren Baghdasaryan
  0 siblings, 0 replies; 4+ messages in thread
From: Suren Baghdasaryan @ 2025-05-13  2:06 UTC (permalink / raw)
  To: Casey Chen; +Cc: linux-mm, kent.overstreet, yzhong

On Mon, May 12, 2025 at 2:02 PM Casey Chen <cachen@purestorage.com> wrote:
>
> On Mon, May 12, 2025 at 1:53 PM Suren Baghdasaryan <surenb@google.com> wrote:
> >
> > On Mon, May 12, 2025 at 12:42 PM Casey Chen <cachen@purestorage.com> wrote:
> > >
> > > If mem_profiling_support is false, for example by
> > > sysctl.vm.mem_profiling=never, alloc_tag_init should skip
> > > module tags allocation, codetag type registration and
> > > procfs init.
> > >
> > > Signed-off-by: Casey Chen <cachen@purestorage.com>
> > > Reviewed-by: Yuanyuan Zhong <yzhong@purestorage.com>
> > > ---
> > >  lib/alloc_tag.c | 34 +++++++++++++++++++---------------
> > >  1 file changed, 19 insertions(+), 15 deletions(-)
> > >
> > > diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
> > > index 25ecc1334b67..7c798778669c 100644
> > > --- a/lib/alloc_tag.c
> > > +++ b/lib/alloc_tag.c
> > > @@ -244,17 +244,6 @@ static void shutdown_mem_profiling(bool remove_file)
> > >         mem_profiling_support = false;
> > >  }
> > >
> > > -static void __init procfs_init(void)
> > > -{
> > > -       if (!mem_profiling_support)
> > > -               return;
> > > -
> > > -       if (!proc_create_seq(ALLOCINFO_FILE_NAME, 0400, NULL, &allocinfo_seq_op)) {
> > > -               pr_err("Failed to create %s file\n", ALLOCINFO_FILE_NAME);
> > > -               shutdown_mem_profiling(false);
> > > -       }
> > > -}
> > > -
> > >  void __init alloc_tag_sec_init(void)
> > >  {
> > >         struct alloc_tag *last_codetag;
> > > @@ -762,19 +751,34 @@ static int __init alloc_tag_init(void)
> > >         };
> > >         int res;
> > >
> > > +       sysctl_init();
> > > +
> > > +       if (!mem_profiling_support) {
> > > +               pr_info("Memory allocation profiling is not supported!\n");
> > > +               return 0;
> > > +       }
> > > +
> > > +       if (!proc_create_seq(ALLOCINFO_FILE_NAME, 0400, NULL, &allocinfo_seq_op)) {
> >
> > I suggest keeping file creation as the last step so that we don't have
> > to remove it if later steps fail.
> >
>
> If the file creation is the last step, how could it clean up codetag
> type registration ? As we miss codetag unregistration function, I
> think codetag type registration should be the last step.

I see. Ok, keeping it here sounds reasonable. Implementing
codetag_unregister_type() just for this failure case would not make
sense. Please go ahead and address the other nits and I think it will
be good to go.

>
> > > +               pr_err("Failed to create %s file\n", ALLOCINFO_FILE_NAME);
> > > +               shutdown_mem_profiling(false);
> > > +               return -EAGAIN;
> >
> > Why EAGAIN? I would just let it fall through returning 0 (after moving
> > this to the end as I suggested in my previous comment).
> >
>
> return 0 is fine to me if this fails. EAGAIN sounds fine too.
>
> > > +       }
> > > +
> > >         res = alloc_mod_tags_mem();
> > > -       if (res)
> > > +       if (res) {
> > > +               pr_err("Failed to allocate module tags\n");
> >
> > The error message is a bit misleading here since we are not allocating
> > module tags but reserving virtual space for them. Maybe:
> > "Failed to reserve address space for module tags"
> >
>
> Sounds good!
>
> > > +               shutdown_mem_profiling(true);
> > >                 return res;
> > > +       }
> > >
> > >         alloc_tag_cttype = codetag_register_type(&desc);
> > >         if (IS_ERR(alloc_tag_cttype)) {
> > > +               pr_err("Failed to register codetag type with desc %s\n", desc.section);
> >
> > pr_err("Allocation tags registration failed, errno = %d\n", ret);
> >
>
> Sounds good too.
>
> > >                 free_mod_tags_mem();
> > > +               shutdown_mem_profiling(true);
> > >                 return PTR_ERR(alloc_tag_cttype);
> > >         }
> > >
> > > -       sysctl_init();
> > > -       procfs_init();
> > > -
> > >         return 0;
> > >  }
> > >  module_init(alloc_tag_init);
> > > --
> > > 2.49.0
> > >


^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2025-05-13  2:07 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2025-05-12 19:42 [PATCH v3] alloc_tag: check mem_profiling_support in alloc_tag_init Casey Chen
2025-05-12 20:53 ` Suren Baghdasaryan
2025-05-12 21:02   ` Casey Chen
2025-05-13  2:06     ` Suren Baghdasaryan

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