Use mutex hint bit in PPC LWARX instructions, where possible. The hint bit makes for a small but measurable performance improvement in access to contended spinlocks.
On the other hand, some PPC chips give an illegal-instruction failure. There doesn't seem to be a completely bulletproof way to tell whether the hint bit will cause an illegal-instruction failure other than by trying it; but most if not all 64-bit PPC machines should accept it, so follow the Linux kernel's lead and assume it's okay to use it in 64-bit builds. Of course we must also check whether the assembler accepts the command, since even with a recent CPU the toolchain could be old. Patch by Manabu Ori, significantly modified by me. Branch ------ master Details ------- http://git.postgresql.org/pg/commitdiff/5cfa8dd3007d7e953c6a03b0fa2215d97c581b0c Modified Files -------------- configure | 62 +++++++++++++++++++++++++++++++++++++++- configure.in | 18 +++++++++++- src/include/pg_config.h.in | 5 ++- src/include/pg_config_manual.h | 18 +++++++++++ src/include/storage/s_lock.h | 4 ++ 5 files changed, 104 insertions(+), 3 deletions(-) -- Sent via pgsql-committers mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-committers
