Re: [Xen-devel] [PATCH 1/2] events/fifo: don't spin indefinitely when setting LINK

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 11.11.13 at 17:03, David Vrabel <david.vrabel@xxxxxxxxxx> wrote:
> +static bool_t evtchn_fifo_set_link(struct domain *d, event_word_t *word,

All you need d for is to get its domain_id, hence it could easily be a
pointer to const.

> +    w = read_atomic(word);
> +
> +    for ( try = 0; try < 4; try++ )
> +    {
> +        ret = try_set_link(word, &w, link);
> +        if ( ret >= 0 )
> +        {
> +            clear_bit(EVTCHN_FIFO_BUSY, word);

Considering that this is another atomic operation, wouldn't it
make sense to have the cmpxchg() at once clear the flag,
and hence you'd need to clear it here only when ret == 0
(which I understand isn't the common case)?

Jan


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