Re: [PATCH for-next] RDMA/efa: Use __GFP_RETRY_MAYFAIL for ring allocations

[Leon Romanovsky <leon@kernel.org>]

On Thu, Sep 17, 2026 at 10:51:01AM +0000, Michael Margolin wrote:
> RQ and CQ ring buffers require physically contiguous memory. On
> systems under memory pressure, high-order allocations can fail
> even when sufficient free memory exists because the allocator
> gives up after a single reclaim and compaction attempt for
> costly-order requests that lack __GFP_RETRY_MAYFAIL.

What sizes did you see fail, and in which flow?

Thanks

> 
> Add __GFP_RETRY_MAYFAIL to the GFP flags in efa_zalloc_mapped()
> to allow retries with escalating compaction priority and release
> of highatomic reserves before giving up.
> 
> Reviewed-by: Firas Jahjah <firasj@amazon.com>
> Reviewed-by: Yonatan Nachum <ynachum@amazon.com>
> Signed-off-by: Michael Margolin <mrgolin@amazon.com>
> ---
>  drivers/infiniband/hw/efa/efa_verbs.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/infiniband/hw/efa/efa_verbs.c b/drivers/infiniband/hw/efa/efa_verbs.c
> index 2d28d68efe77..0b0396e190f2 100644
> --- a/drivers/infiniband/hw/efa/efa_verbs.c
> +++ b/drivers/infiniband/hw/efa/efa_verbs.c
> @@ -190,7 +190,7 @@ static void *efa_zalloc_mapped(struct efa_dev *dev, dma_addr_t *dma_addr,
>  {
>  	void *addr;
>  
> -	addr = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
> +	addr = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO | __GFP_RETRY_MAYFAIL);
>  	if (!addr)
>  		return NULL;
>  
> -- 
> 2.47.3
>