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.
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(-)
pgsql-committers by date
|Next:||From: Bruce Momjian||Date: 2012-01-02 13:49:14|
|Subject: pgsql: Add comment about skipping binary files for copyright changes.|
|Previous:||From: Bruce Momjian||Date: 2012-01-02 03:27:46|
|Subject: pgsql: Update copyright git skip comment.|