On Wed, 31 Jul 2019, Zebediah Figura wrote: > On 7/31/19 7:06 AM, Peter Zijlstra wrote: > > On Tue, Jul 30, 2019 at 06:06:02PM -0400, Gabriel Krisman Bertazi wrote: > > > This is a new futex operation, called FUTEX_WAIT_MULTIPLE, which allows > > > a thread to wait on several futexes at the same time, and be awoken by > > > any of them. In a sense, it implements one of the features that was > > > supported by pooling on the old FUTEX_FD interface. > > > > > > My use case for this operation lies in Wine, where we want to implement > > > a similar interface available in Windows, used mainly for event > > > handling. The wine folks have an implementation that uses eventfd, but > > > it suffers from FD exhaustion (I was told they have application that go > > > to the order of multi-milion FDs), and higher CPU utilization. > > > > So is multi-million the range we expect for @count ? > > > > Not in Wine's case; in fact Wine has a hard limit of 64 synchronization > primitives that can be waited on at once (which, with the current user-side > code, translates into 65 futexes). The exhaustion just had to do with the > number of primitives created; some programs seem to leak them badly.
And how is the futex approach better suited to 'fix' resource leaks? Thanks, tglx