CVS commit: src/libexec/ld.elf_so

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Wed Jun 16 21:53:51 UTC 2021

Modified Files:
        src/libexec/ld.elf_so: rtld.c

Log Message:
ld.elf_so(1): Omit needless membar_enter.

The use of membar_enter is to separate atomic r/m/w on a lock from
the body of the critical section so two different critical sections
happen in order:

                body of previous critical section;

        exit critical section:
                membar_exit();
                atomic_r/m/w(lock stuff);

        enter critical section:
                atomic_r/m/w(lock stuff);
                membar_enter();

                body of next critical section;

_rtld_shared_enter does this, but it _also_ issued an extraneous
membar_enter before the atomic_r/m/w part, which doesn't impose any
semantically important order but may cost some performance.


To generate a diff of this commit:
cvs rdiff -u -r1.208 -r1.209 src/libexec/ld.elf_so/rtld.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.