Re: [PATCH] net: fix the per task frag allocator size

[Yunsheng Lin <linyunsheng@huawei.com>]

On 2018/11/23 10:03, Li RongQing wrote:
> when fill task frag, 32K pages, 128MB memory is asked, it
> hardly successes when system has memory stress
> 
> and commit '5640f7685831 ("net: use a per task frag allocator")'
> said it wants 32768 bytes, not 32768 pages:
> 
> 	 "(up to 32768 bytes per frag, thats order-3 pages on x86)"
> 
> Fixes: 5640f7685831e ("net: use a per task frag allocator")
> Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
> Signed-off-by: Li RongQing <lirongqing@baidu.com>
> ---
>  net/core/sock.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/core/sock.c b/net/core/sock.c
> index 6d7e189e3cd9..e3cbefeedf5c 100644
> --- a/net/core/sock.c
> +++ b/net/core/sock.c
> @@ -2186,8 +2186,8 @@ static void sk_leave_memory_pressure(struct sock *sk)
>  	}
>  }
>  
> -/* On 32bit arches, an skb frag is limited to 2^15 */
> -#define SKB_FRAG_PAGE_ORDER	get_order(32768)
> +/* On 32bit arches, an skb frag is limited to 2^15 bytes*/
> +#define SKB_FRAG_PAGE_ORDER	get_order(8)

get_order(8) returns zero here if I understood it correctly.


>  
>  /**
>   * skb_page_frag_refill - check that a page_frag contains enough room
>