Re: [PATCH 1/1] RDMA/rxe: Fix blktests srp lead kernel panic with 64k page size

[Bart Van Assche <bvanassche@acm.org>]

On 10/19/23 23:54, Zhijian Li (Fujitsu) wrote:
> Add and Hi Bart,
> 
> Yi reported a crash[1] when PAGE_SIZE is 64K
> [1]https://lore.kernel.org/all/CAHj4cs9XRqE25jyVw9rj9YugffLn5+f=1znaBEnu1usLOciD+g@mail.gmail.com/T/
> 
> The root cause is unknown so far, but I notice that SRP over RXE always uses MR with page_size
> 4K = MAX(4K, min(device_support_page_size)) even though the device supports 64K page size.
> * RXE device support 4K ~ 2G page size
> 
> 
> 4024         /*
> 4025          * Use the smallest page size supported by the HCA, down to a
> 4026          * minimum of 4096 bytes. We're unlikely to build large sglists
> 4027          * out of smaller entries.
> 4028          */
> 4029         mr_page_shift           = max(12, ffs(attr->page_size_cap) - 1);
> 4030         srp_dev->mr_page_size   = 1 << mr_page_shift;
> 4031         srp_dev->mr_page_mask   = ~((u64) srp_dev->mr_page_size - 1);
> 4032         max_pages_per_mr        = attr->max_mr_size;
> 
> 
> I doubt if we can use PAGE_SIZE MR if the device supports it.

Hi Zhijian,

Thank you for having Cc-ed me. How about changing "12" in the above code
into PAGE_SHIFT?

Thanks,

Bart.