[PATCH] aio: remove superfluous kiocb member initialization (212079cf) · Commits · 戴 / test

This patch removes superfluous kiocb member initialization in the AIO allocation and deallocation path. For example, in really_put_req(), right before kiocb is returned to slab, 5 variables are reset to NULL. The same variables will be initialized at the kiocb allocation time, so why bother reset them knowing that they will be set to valid data at alloc time? Another example: ki_retry is initialized in __aio_get_req, but is initialized again in io_submit_one. Signed-off-by:

Ken Chen <kenneth.w.chen@intel.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Suparna Bhattacharya <suparna@in.ibm.com> Signed-off-by:

Andrew Morton <akpm@osdl.org> Signed-off-by:

Linus Torvalds <torvalds@osdl.org>

fs/aio.c

+1 −10

Original line number	Diff line number	Diff line
		@@ -405,7 +405,6 @@ static struct kiocb fastcall __aio_get_req(struct kioctx ctx)
		req->ki_ctx = ctx;
		req->ki_cancel = NULL;
		req->ki_retry = NULL;
		req->ki_obj.user = NULL;
		req->ki_dtor = NULL;
		req->private = NULL;
		INIT_LIST_HEAD(&req->ki_run_list);
		@@ -451,11 +450,6 @@ static inline void really_put_req(struct kioctx ctx, struct kiocb req)
		{
		if (req->ki_dtor)
		req->ki_dtor(req);
		req->ki_ctx = NULL;
		req->ki_filp = NULL;
		req->ki_obj.user = NULL;
		req->ki_dtor = NULL;
		req->private = NULL;
		kmem_cache_free(kiocb_cachep, req);
		ctx->reqs_active--;

		@@ -1515,8 +1509,7 @@ int fastcall io_submit_one(struct kioctx ctx, struct iocb __user user_iocb,
		}

		req->ki_filp = file;
		iocb->aio_key = req->ki_key;
		ret = put_user(iocb->aio_key, &user_iocb->aio_key);
		ret = put_user(req->ki_key, &user_iocb->aio_key);
		if (unlikely(ret)) {
		dprintk("EFAULT: aio_key\n");
		goto out_put_req;
		@@ -1531,8 +1524,6 @@ int fastcall io_submit_one(struct kioctx ctx, struct iocb __user user_iocb,
		req->ki_opcode = iocb->aio_lio_opcode;
		init_waitqueue_func_entry(&req->ki_wait, aio_wake_function);
		INIT_LIST_HEAD(&req->ki_wait.task_list);
		req->ki_run_list.next = req->ki_run_list.prev = NULL;
		req->ki_retry = NULL;
		req->ki_retried = 0;
		req->ki_kicked = 0;
		req->ki_queued = 0;

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