Re: [Sks-devel] Fwd: Re: sks (fast)build memory/cache problem

[Jeffrey Johnson]

On Jul 2, 2012, at 7:37 AM, Kristian Fiskerstrand wrote:

This is rarely necessary and should be done only when the
        default configuration selects the wrong mutex implementation.

Is Gentoo3 or Gentoo4 selecting the wrong mutex implementation?

The deep underlying reason for using pthread_mutex is

Do multi-thread and multi-process locks use the same mechanism?

The pthread_mutex implementation using futexes is likely intrinsically faster,

and pthread_mutexes unify interprocess and inter-thread locks in the same mechanism.

Statically library linking in a multlib environment has some tricky build

prerequsites to find pthread_mutex() in an arch-specific static library

on a multlib peculiar path. Add the build prereqa, not change the mutex

implementation, is the better solution imho.

The --enable=o_direct should likely not be used on linux too:

http://kerneltrap.org/node/7563

I've personally tried O_DIRECT with no improvement tuning bdb in rpm.

But they are all build options to use however one wishes: but the criteria

to decide what options to use are rather murky.

Here is what I have used for years (including RHL/RHEL3/RHEL4 Berkeley DB)

can be found in many dbXY.spec files is mostly similar to what you used:

        %configure -C --srcdir=../dist/ \

                --includedir='${prefix}/include/%{name}' \

                --program-transform-name=s,^db,%{name}, \

                --enable-compat185 --enable-dump185 \

                --enable-shared --enable-static \

                --enable-cxx \

                --enable-sql \

                --enable-sql_codegen \

                --enable-stl \

%ifarch %{java_arches}

                --enable-java \

%else

                --disable-java \

%endif

                # --enable-jdbc \

                # --with-cryptography=yes \

                # --with-stacksize=SIZE \

                # --with-uniquename=SUFFIX \

                # --with-pic \

                # --with-gnu-ld \

                # --enable-jdbc --with-jdbc=DIR \

                # --enable-perfmon-statistics \

                # --enable-dtrace \

                # --enable-systemtap \

                # --enable-umrw \

                # --enable-test \

                # --enable-debug --enable-debug_rop --enable-debug_wop \

                # --enable-diagnostic \

DIsclaimer:

They are all build options to use however one wishes: but the criteria

to decide what options to use is rather murky. YMMV, everyone's does.

hth

73 de Jeff