Re: [patch/rfc] eventfd semaphore-like behavior

[Michael Kerrisk]

On Thu, Feb 5, 2009 at 12:45 PM, Ulrich Drepper <drepper@xxxxxxxxx> wrote:
> On Wed, Feb 4, 2009 at 3:05 PM, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>> How would you recommend that userspace determine whether its kernel
>> supports this feature, bearing in mind that someone might backport this
>> patch into arbitrarily earlier kernel versions?
>
>   fd = eventfd2 (CNT, EFD_SEMAPHORE);
>   if (fd == -1 && errno == EINVAL)
>     puts("cannot handled EFD_SEMAPHORE");

Crossed mails.  Ulrich put the point more succinctly.


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Michael Kerrisk
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