Re: [PATCH 3/5] io_uring/zcrx: let zcrx choose region for mmaping

[Pavel Begunkov <asml.silence@gmail.com>]

On 4/18/25 16:35, David Wei wrote:
> On 2025-04-16 08:21, Pavel Begunkov wrote:
>> In preparation for adding multiple ifqs, add a helper returning a region
>> for mmaping zcrx refill queue. For now it's trivial and returns the same
>> ctx global ->zcrx_region.
>>
>> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
>> ---
>>   io_uring/memmap.c | 10 ++++++----
>>   io_uring/zcrx.c   | 10 ++++++++++
>>   io_uring/zcrx.h   |  7 +++++++
>>   3 files changed, 23 insertions(+), 4 deletions(-)
>>
>> diff --git a/io_uring/memmap.c b/io_uring/memmap.c
>> index 76fcc79656b0..e53289b8d69d 100644
>> --- a/io_uring/memmap.c
>> +++ b/io_uring/memmap.c
>> @@ -13,6 +13,7 @@
>>   #include "memmap.h"
>>   #include "kbuf.h"
>>   #include "rsrc.h"
>> +#include "zcrx.h"
>>   
>>   static void *io_mem_alloc_compound(struct page **pages, int nr_pages,
>>   				   size_t size, gfp_t gfp)
>> @@ -258,7 +259,9 @@ static struct io_mapped_region *io_mmap_get_region(struct io_ring_ctx *ctx,
>>   						   loff_t pgoff)
>>   {
>>   	loff_t offset = pgoff << PAGE_SHIFT;
>> -	unsigned int bgid;
>> +	unsigned int id;
>> +
>> +	id = (offset & ~IORING_OFF_MMAP_MASK) >> IORING_OFF_PBUF_SHIFT;
> 
> We using the same IORING_OFF_PBUF_SHIFT?

Let me check that, and also it likely doesn't return the right
value to the user as well.

-- 
Pavel Begunkov