Messages in this thread | | | Subject | Re: [PATCH 1/2] x86-64 TIF flags for debug regs and io bitmap in ctxsw | From | Arjan van de Ven <> | Date | Tue, 04 Jul 2006 09:51:49 +0200 |
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> - } > - } > + if (unlikely((task_thread_info(next_p)->flags & _TIF_WORK_CTXSW)) > + || test_tsk_thread_flag(prev_p, TIF_IO_BITMAP)) > + __switch_to_xtra(prev_p, next_p, tss);
well isn't this replacing an if() (which isn't cheap but also not expensive, due to unlikely()) with an atomic operation (which *is* expensive) ?
That to me doesn't make this sound like an actual win....
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