From: Stefan Metzmacher <[email protected]>
To: Pavel Begunkov <[email protected]>,
Jens Axboe <[email protected]>,
[email protected]
Subject: Re: [PATCH 3/3] io_uring: refactor sendmsg/recvmsg iov managing
Date: Fri, 5 Feb 2021 08:17:57 +0100 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <ac7dc756e811000751c9cc8fba5d03cc73da314a.1612486458.git.asml.silence@gmail.com>
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Hi Pavel,
> static int io_sendmsg_copy_hdr(struct io_kiocb *req,
> struct io_async_msghdr *iomsg)
> {
> - iomsg->iov = iomsg->fast_iov;
> iomsg->msg.msg_name = &iomsg->addr;
> + iomsg->free_iov = iomsg->fast_iov;
Why this? Isn't the idea of this patch that free_iov is never == fast_iov?
> @@ -4704,10 +4703,11 @@ static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
> if (copy_from_user(iomsg->fast_iov, uiov, sizeof(*uiov)))
> return -EFAULT;
> sr->len = iomsg->fast_iov[0].iov_len;
> - iomsg->iov = NULL;
> + iomsg->free_iov = NULL;
> } else {
> + iomsg->free_iov = iomsg->fast_iov;
The same here...
> ret = __import_iovec(READ, uiov, iov_len, UIO_FASTIOV,
> - &iomsg->iov, &iomsg->msg.msg_iter,
> + &iomsg->free_iov, &iomsg->msg.msg_iter,
> false);
> if (ret > 0)
> ret = 0;
> @@ -4746,10 +4746,11 @@ static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
> if (clen < 0)
> return -EINVAL;
> sr->len = clen;
> - iomsg->iov = NULL;
> + iomsg->free_iov = NULL;
> } else {
> + iomsg->free_iov = iomsg->fast_iov;
And here...
> ret = __import_iovec(READ, (struct iovec __user *)uiov, len,
> - UIO_FASTIOV, &iomsg->iov,
> + UIO_FASTIOV, &iomsg->free_iov,
> &iomsg->msg.msg_iter, true);
> if (ret < 0)
> return ret;
> @@ -4872,8 +4867,8 @@ static int io_recvmsg(struct io_kiocb *req, bool force_nonblock,
>
> if (req->flags & REQ_F_BUFFER_SELECTED)
> cflags = io_put_recv_kbuf(req);
> - if (kmsg->iov != kmsg->fast_iov)
> - kfree(kmsg->iov);
> + if (kmsg->free_iov)
> + kfree(kmsg->free_iov);
kfree() handles NULL, or is this a hot path and we want to avoid a function call?
metze
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next prev parent reply other threads:[~2021-02-05 7:55 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-05 0:57 [PATCH for-next 0/3] sendmsg/recvmsg cleanup Pavel Begunkov
2021-02-05 0:57 ` [PATCH 1/3] io_uring: set msg_name on msg fixup Pavel Begunkov
2021-02-05 0:57 ` [PATCH 2/3] io_uring: clean iov usage for recvmsg buf select Pavel Begunkov
2021-02-05 0:58 ` [PATCH 3/3] io_uring: refactor sendmsg/recvmsg iov managing Pavel Begunkov
2021-02-05 7:17 ` Stefan Metzmacher [this message]
2021-02-05 9:48 ` Pavel Begunkov
2021-02-05 9:58 ` Stefan Metzmacher
2021-02-05 10:06 ` Pavel Begunkov
2021-02-05 14:45 ` Jens Axboe
2021-02-05 14:57 ` Pavel Begunkov
2021-02-05 14:46 ` [PATCH for-next 0/3] sendmsg/recvmsg cleanup Jens Axboe
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