Hidetoshi Seto <seto.hidetoshi@xxxxxxxxxxxxxx> writes: > I suspected the value of r28. > So I just relocate "consuming" of r28 to early stage. > > <PATCH> >> Index: linux-2.6.21/arch/ia64/kernel/fsys.S >> =================================================================== >> --- linux-2.6.21.orig/arch/ia64/kernel/fsys.S >> +++ linux-2.6.21/arch/ia64/kernel/fsys.S >> @@ -247,6 +247,9 @@ >> .time_redo: >> .pred.rel.mutex p8,p9,p10 >> ld4.acq r28 = [r29] // xtime_lock.sequence. Must come first for locking purposes >> + ;; >> + and r28 = ~1,r28 // Make sequence even to force retry if odd >> + ;; >> (p8) mov r2 = ar.itc // CPU_TIMER. 36 clocks latency!!! >> add r22 = IA64_TIME_INTERPOLATOR_LAST_COUNTER_OFFSET,r20 >> (p9) ld8 r2 = [r30] // readq(ti->address). Could also have latency issues.. >> @@ -284,7 +287,6 @@ >> (p15) ld8 r17 = [r19],-IA64_TIMESPEC_TV_NSEC_OFFSET >> (p7) cmp.ne p7,p0 = r25,r3 // if cmpxchg not successful redo >> // simulate tbit.nz.or p7,p0 = r28,0 >> - and r28 = ~1,r28 // Make sequence even to force retry if odd >> getf.sig r2 = f8 >> mf >> add r8 = r8,r18 // Add time interpolator offset > </PATCH> > > What a surprise! This patch solves the problem! How can the register lose its contents? The only thing that can make a difference is the stop bit. Andreas. -- Andreas Schwab, SuSE Labs, schwab@xxxxxxx SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany PGP key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different." - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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