Subject: Re: splx() optimization [was Re: SMP re-eetrancy in "bottom half" drivers]
To: Stephan Uphoff <>
From: David Laight <>
List: tech-kern
Date: 05/30/2005 18:31:02
On Sat, May 28, 2005 at 04:37:58PM -0400, Stephan Uphoff wrote:
> The attached patch should drastically reduce the cost of splx() calls
> on P4s as it removes expensive cli/sti operations (> 70 cycles)


I guess the fact that 'cli; nop; sti' is required to let in pending
interrupts dosn't help.


David Laight: