On 4/21/22 7:15 PM, Kanchan Joshi wrote:
> On Thu, Apr 21, 2022 at 1:37 PM Stefan Roesch <shr@xxxxxx> wrote:
>>
>> This adds the overflow processing for large CQE's.
>>
>> This adds two parameters to the io_cqring_event_overflow function and
>> uses these fields to initialize the large CQE fields.
>>
>> Allocate enough space for large CQE's in the overflow structue. If no
>> large CQE's are used, the size of the allocation is unchanged.
>>
>> The cqe field can have a different size depending if its a large
>> CQE or not. To be able to allocate different sizes, the two fields
>> in the structure are re-ordered.
>>
>> Co-developed-by: Jens Axboe <axboe@xxxxxxxxx>
>> Signed-off-by: Stefan Roesch <shr@xxxxxx>
>> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
>> ---
>> fs/io_uring.c | 26 +++++++++++++++++++-------
>> 1 file changed, 19 insertions(+), 7 deletions(-)
>>
>> diff --git a/fs/io_uring.c b/fs/io_uring.c
>> index ff6229b6df16..50efced63ec9 100644
>> --- a/fs/io_uring.c
>> +++ b/fs/io_uring.c
>> @@ -220,8 +220,8 @@ struct io_mapped_ubuf {
>> struct io_ring_ctx;
>>
>> struct io_overflow_cqe {
>> - struct io_uring_cqe cqe;
>> struct list_head list;
>> + struct io_uring_cqe cqe;
>> };
>>
>> struct io_fixed_file {
>> @@ -2016,13 +2016,17 @@ static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force)
>> while (!list_empty(&ctx->cq_overflow_list)) {
>> struct io_uring_cqe *cqe = io_get_cqe(ctx);
>> struct io_overflow_cqe *ocqe;
>> + size_t cqe_size = sizeof(struct io_uring_cqe);
>> +
>> + if (ctx->flags & IORING_SETUP_CQE32)
>> + cqe_size <<= 1;
>>
>> if (!cqe && !force)
>> break;
>> ocqe = list_first_entry(&ctx->cq_overflow_list,
>> struct io_overflow_cqe, list);
>> if (cqe)
>> - memcpy(cqe, &ocqe->cqe, sizeof(*cqe));
>> + memcpy(cqe, &ocqe->cqe, cqe_size);
>> else
>> io_account_cq_overflow(ctx);
>>
>> @@ -2111,11 +2115,15 @@ static __cold void io_uring_drop_tctx_refs(struct task_struct *task)
>> }
>>
>> static bool io_cqring_event_overflow(struct io_ring_ctx *ctx, u64 user_data,
>> - s32 res, u32 cflags)
>> + s32 res, u32 cflags, u64 extra1, u64 extra2)
>> {
>> struct io_overflow_cqe *ocqe;
>> + size_t ocq_size = sizeof(struct io_overflow_cqe);
>>
>> - ocqe = kmalloc(sizeof(*ocqe), GFP_ATOMIC | __GFP_ACCOUNT);
>> + if (ctx->flags & IORING_SETUP_CQE32)
>
> This can go inside in a bool variable, as this check is repeated in
> this function.
V3 will have this change.
