Re: [PATCH] perf: fix ring_buffer perf_output_space() boundarycalculation

From: Peter Zijlstra
Date: Mon Mar 18 2013 - 08:59:49 EST


On Mon, 2013-03-18 at 13:48 +0100, Stephane Eranian wrote:
> if (!rb->writable)
> - return true;
> + return false;


writable means user writable (VM_WRITE); the difference is that a
!VM_WRITE buffer will simply over-write its own tail whereas a VM_WRITE
buffer will drop events.

So returning true for !VM_WRITE makes sense, there's always space.

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