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io_uring/kbuf: remove legacy kbuf bulk allocation

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Legacy provided buffers are slow and discouraged in favour of the ring
variant. Remove the bulk allocation to keep it simpler as we don't care
about performance.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a064d70370e590efed8076e9501ae4cfc20fe0ca.1738724373.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2025-02-05 11:36:42 +00:00 • committed by Jens Axboe
parent 92a3bac9a5
commit 7919292a96
1 changed files with 5 additions and 25 deletions
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30
io_uring/kbuf.c
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@ -501,12 +501,9 @@ int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe
return 0;
}
#define IO_BUFFER_ALLOC_BATCH 64
static int io_refill_buffer_cache(struct io_ring_ctx *ctx)
{
struct io_buffer *bufs[IO_BUFFER_ALLOC_BATCH];
int allocated;
struct io_buffer *buf;
/*
* Completions that don't happen inline (eg not under uring_lock) will
@ -524,27 +521,10 @@ static int io_refill_buffer_cache(struct io_ring_ctx *ctx)
spin_unlock(&ctx->completion_lock);
}
/*
* No free buffers and no completion entries either. Allocate a new
* batch of buffer entries and add those to our freelist.
*/
allocated = kmem_cache_alloc_bulk(io_buf_cachep, GFP_KERNEL_ACCOUNT,
ARRAY_SIZE(bufs), (void **) bufs);
if (unlikely(!allocated)) {
/*
* Bulk alloc is all-or-nothing. If we fail to get a batch,
* retry single alloc to be on the safe side.
*/
bufs[0] = kmem_cache_alloc(io_buf_cachep, GFP_KERNEL);
if (!bufs[0])
return -ENOMEM;
allocated = 1;
}
while (allocated)
list_add_tail(&bufs[--allocated]->list, &ctx->io_buffers_cache);
buf = kmem_cache_alloc(io_buf_cachep, GFP_KERNEL);
if (!buf)
return -ENOMEM;
list_add_tail(&buf->list, &ctx->io_buffers_cache);
return 0;
}