Hi!
> Abstract out the calculation of there being sufficient Tx buffer space.
> This is reproduced several times in the rxrpc sendmsg code.
I don't think this is suitable for stable. It does not fix anything.
> +/*
> + * Return true if there's sufficient Tx queue space.
> + */
> +static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
> +{
> + unsigned int win_size =
> + min_t(unsigned int, call->tx_winsize,
> + call->cong_cwnd + call->cong_extra);
> + rxrpc_seq_t tx_win = READ_ONCE(call->tx_hard_ack);
> +
> + if (_tx_win)
> + *_tx_win = tx_win;
Plus, this is very very strange. Most callers pass NULL here, so we
do READ_ONCE(call->tx_hard_ack) and it can't be optimized out, and
then we drop the result.
> @@ -72,9 +85,7 @@ static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
> set_current_state(TASK_UNINTERRUPTIBLE);
>
> tx_win = READ_ONCE(call->tx_hard_ack);
> - if (call->tx_top - tx_win <
> - min_t(unsigned int, call->tx_winsize,
> - call->cong_cwnd + call->cong_extra))
> + if (rxrpc_check_tx_space(call, &tx_win))
> return 0;
>
> if (call->state >= RXRPC_CALL_COMPLETE)
And the remaining caller already has right value in tx_win, and it is
discarded and READ again.
This does not make sense.
Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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