On Thu, 2014-11-27 at 17:48 +0530, Madhavan Srinivasan wrote: > - I really appreciate feedback on the patchset. > - Kindly comment if I should try with any other benchmark or > workload to check the numbers. > - Also, kindly recommand any know stress test for CR > > Makefile | 6 ++ > arch/powerpc/include/asm/exception-64s.h | 21 +++++- > arch/powerpc/kernel/entry_64.S | 106 > ++++++++++++++++++++++++++++++- > arch/powerpc/kernel/exceptions-64s.S | 2 +- > arch/powerpc/kernel/head_64.S | 8 +++ > 5 files changed, 138 insertions(+), 5 deletions(-)
Patch 2/2 enables this for all PPC64, not just book3s -- so please don't forget about the book3e exception paths (also MSR[GS] for KVM, but aren't most if not all the places you're checking for HV mode after KVM would have taken control? Or am I missing something about how book3s KVM works?). Or, if you don't want to do that, change patch 2/2 to be book3s only and ifdef-protect the changes to common exception code. > @@ -224,8 +243,26 @@ syscall_exit: > BEGIN_FTR_SECTION > stdcx. r0,0,r1 /* to clear the reservation */ > END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) > +BEGIN_FTR_SECTION > + lis r4,4096 > + rldicr r4,r4,32,31 > + mr r6,r4 > + ori r4,r4,16384 > + and r4,r8,r4 > + cmpd cr3,r6,r4 > + beq cr3,65f > + mtcr r5 > +FTR_SECTION_ELSE > andi. r6,r8,MSR_PR > - ld r4,_LINK(r1) > + beq 65f > + mtcr r5 > + nop > + nop > + nop > + nop > + nop > +ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE) > +65: ld r4,_LINK(r1) > > beq- 1f > ACCOUNT_CPU_USER_EXIT(r11, r12) > @@ -234,7 +271,11 @@ END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) > 1: ld r2,GPR2(r1) > ld r1,GPR1(r1) > mtlr r4 > +#ifdef CONFIG_PPC64 > + mtcrf 0xFB,r5 > +#else > mtcr r5 > +#endif mtcrf with more than one CRn being updated is expensive on Freescale chips (and this isn't a book3s-only code path). Why do you need to do it twice? I don't see where either r5 or cr5 are messed with between the two places... -Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
