On Wed, Aug 07, 2013 at 01:53:57PM -0700, Kent Overstreet wrote: > On Wed, Aug 07, 2013 at 10:28:18PM +0200, Ben Hutchings wrote: > > As Kent said back in 2011 (commit 84759c6d18c5), bcache needs > > {down,up}_read_non_owner(). But these are not implemented by the -rt > > patchset when PREEMPT_RT_FULL is enabled. Can they be added, or is > > there a fundamental conflict here? > > You should be able to cherry pick > 84759c6d18c5144432781ddca037d929ee9db8a5 (Revert "rw_semaphore: remove > up/down_read_non_owner") - that went in when bcache was merged. That doesn't help with PREEMPT_RT_FULL because include/linux/rwsem.h looks like:
[ ... some includes ... ] #ifdef CONFIG_PREEMPT_RT_FULL #include <linux/rwsem_rt.h> #else /* PREEMPT_RT_FULL */ [ ... vanilla content including definitions of {down,up}_read_non_owner] #endif So Ben's question was how (if at all) we should implement {down,up}_read_non_owner for PREEMPT_RT_FULL. Is it save to just use the vanilla implementation on RT? Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/