Re: [patch] 2.6.8.1: display committed memory limit and available in meminfo

[Frank Hirtz <fhirtz@redhat.com>]

Hi,

I'm new to the list, and was wondering since I've not seen any feedback on this 
patch whether that was because the patch is not good/a good idea or whether no 
one has an opinion on displaying this information. I'd like to get this included 
and any feedback would be greatly appreciated.

Thanks again,

Frank.

Frank Hirtz wrote:

> The following patch will have the committed memory limit (per the 
> current overcommit ratio) and the amount of memory remaining under this 
> limit displayed in meminfo.
> 
> It's presently somewhat difficult to use the strict memory overcommit 
> settings as it's somewhat difficult to determine the amount of memory 
> remaining under the cap. This patch would make using strict overcommit a 
> good bit simpler. Does such an addition seem reasonable?
> 
> Thank you,
> 
> Frank.
> 
> 
> ------------------------------------------------------------------------
> 
> --- linux-2.6.8.1/fs/proc/proc_misc.c		2004-08-18 16:32:07.000000000 -0400
> +++ linux-2.6.8.1.new/fs/proc/proc_misc.c	2004-08-18 16:55:47.000000000 -0400
> @@ -153,7 +153,7 @@
>  				 int count, int *eof, void *data)
>  {
>  	struct sysinfo i;
> -	int len, committed;
> +	int len, committed, allowed;
>  	struct page_state ps;
>  	unsigned long inactive;
>  	unsigned long active;
> @@ -171,6 +171,8 @@
>  	si_meminfo(&i);
>  	si_swapinfo(&i);
>  	committed = atomic_read(&vm_committed_space);
> +	allowed = ((totalram_pages - hugetlb_total_pages()) 
> +		* sysctl_overcommit_ratio / 100) + total_swap_pages;
>  
>  	vmtot = (VMALLOC_END-VMALLOC_START)>>10;
>  	vmi = get_vmalloc_info();
> @@ -198,7 +200,9 @@
>  		"Writeback:    %8lu kB\n"
>  		"Mapped:       %8lu kB\n"
>  		"Slab:         %8lu kB\n"
> +		"CommitLimit:  %8lu kB\n"
>  		"Committed_AS: %8u kB\n"
> +		"CommitAvail:  %8ld kB\n"
>  		"PageTables:   %8lu kB\n"
>  		"VmallocTotal: %8lu kB\n"
>  		"VmallocUsed:  %8lu kB\n"
> @@ -220,7 +224,9 @@
>  		K(ps.nr_writeback),
>  		K(ps.nr_mapped),
>  		K(ps.nr_slab),
> +		K(allowed),
>  		K(committed),
> +		K(allowed - committed),
>  		K(ps.nr_page_table_pages),
>  		vmtot,
>  		vmi.used,