Re: [PATCH libibverbs] Allow use of huge pages in multiple calls to ibv_fork_init

[Doug Ledford <dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

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On 2/3/2016 6:42 AM, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> 
> Setting the environment variable RDMAV_HUGEPAGES_SAFE tells the library
> to check the underlying page size used by the kernel for memory regions.
> This is required if an application uses huge pages either directly or
> indirectly via a library such as libhugetlbfs.
> 
> The check of this variable was performed at the first call to
> ibv_fork_init. This caused to unpredicted behavior in complex
> applications with multiple underlying libraries.
> 
> The proposed change will allow support of huge pages without relying on
> ibv_fork_init calls order.

Thanks, applied.

> Signed-off-by: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> ---
>  src/memory.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/src/memory.c b/src/memory.c
> index e9d1eecd9eab..89509c6e356f 100644
> --- a/src/memory.c
> +++ b/src/memory.c
> @@ -140,6 +140,9 @@ int ibv_fork_init(void)
>  	int ret;
>  	unsigned long size;
>  
> +	if (getenv("RDMAV_HUGEPAGES_SAFE"))
> +		huge_page_enabled = 1;
> +
>  	if (mm_root)
>  		return 0;
>  
> @@ -153,11 +156,6 @@ int ibv_fork_init(void)
>  	if (posix_memalign(&tmp, page_size, page_size))
>  		return ENOMEM;
>  
> -	if (getenv("RDMAV_HUGEPAGES_SAFE"))
> -		huge_page_enabled = 1;
> -	else
> -		huge_page_enabled = 0;
> -
>  	if (huge_page_enabled) {
>  		size = get_page_size(tmp);
>  		tmp_aligned = (void *) ((uintptr_t) tmp & ~(size - 1));
> 



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