Extend shmem proc_meminfo(5)

Extend shmem proc_meminfo(5)

[Carsten Grohmann]

Hi Alejandro,

currently shmem in proc_meminfo(5) is described with "Amount of memory consumed in tmpfs(5) filesystems.". 

I think, that's incomplete, as the other types of shares memory are missing.

Therefore, I suggest to change this statement to:

"Amount of memory consumed in tmpfs(5) filesystems, System V and POSIX shared memory, as well as shared anonymous mappings (MAP_SHARED|MAP_ANONYMOUS)."

Regards,
Carsten

Re: Extend shmem proc_meminfo(5)

[Alejandro Colomar]

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Hi Carsten,

On Fri, May 23, 2025 at 12:26:17PM +0200, Carsten Grohmann wrote:
> Hi Alejandro,
> 
> currently shmem in proc_meminfo(5) is described with "Amount of memory consumed in tmpfs(5) filesystems.". 
> 
> I think, that's incomplete, as the other types of shares memory are missing.

Thanks for the report!

> 
> Therefore, I suggest to change this statement to:
> 
> "Amount of memory consumed in tmpfs(5) filesystems, System V and POSIX shared memory, as well as shared anonymous mappings (MAP_SHARED|MAP_ANONYMOUS)."

Does this sound good to you?

	man/man5/proc_meminfo.5: Shmem also accounts for other types of shared memory

	Reported-by: Carsten Grohmann <carstengrohmann@gmx.de>
	Message-ID: <20250523122617.48cf9feb@max.localdomain>

	alx@devuan:/srv/alx/src/linux/man-pages/man-pages/contrib$ git diff
	diff --git i/man/man5/proc_meminfo.5 w/man/man5/proc_meminfo.5
	index c7d201f79..ee4ba2062 100644
	--- i/man/man5/proc_meminfo.5
	+++ w/man/man5/proc_meminfo.5
	@@ -150,7 +150,11 @@ .SH DESCRIPTION
	 .IR Shmem " %lu (since Linux 2.6.32)"
	 Amount of memory consumed in
	 .BR tmpfs (5)
	-filesystems.
	+filesystems,
	+System V,
	+and POSIX shared memory,
	+as well as shared anonymous mappings
	+.RI ( MAP_SHARED|MAP_ANONYMOUS ).
	 .TP
	 .IR KReclaimable " %lu (since Linux 4.20)"
	 Kernel allocations that the kernel will attempt to reclaim
	alx@devuan:/srv/alx/src/linux/man-pages/man-pages/contrib$ MANWIDTH=72 diffman-git 
	--- HEAD:man/man5/proc_meminfo.5
	+++ ./man/man5/proc_meminfo.5
	@@ -123,7 +123,9 @@
			    mmap(2)), such as libraries.
	 
		     Shmem %lu (since Linux 2.6.32)
	-                   Amount of memory consumed in tmpfs(5) filesystems.
	+                   Amount of memory consumed in tmpfs(5) filesystems,
	+                   System V, and POSIX shared memory, as well as shared
	+                   anonymous mappings (MAP_SHARED|MAP_ANONYMOUS).
	 
		     KReclaimable %lu (since Linux 4.20)
			    Kernel allocations that the kernel will attempt to


Have a lovely day!
Alex

-- 
<https://www.alejandro-colomar.es/>

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