This allows for rtld to not issue two sigprocmask(2) syscalls for each symbol binding operation in single-threaded processes. Rtld needs to block signals as part of locking to ensure signal safety of the bind process, because signal handlers might need to lazily resolve symbol references. As result, number of syscalls issued on startup by simple programs not using libthr, is typically reduced 2x. For instance, for hello world, I see: non-sigfastblock # (truss ./hello > /dev/null) |& wc -l 63 sigfastblock # (truss ./hello > /dev/null) |& wc -l 37 Tested by: pho Disscussed with: cem, emaste, jilles Sponsored by: The FreeBSD Foundation Differential revision: https://reviews.freebsd.org/D12773 |
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libc_private.h | ||
Makefile.inc | ||
namespace.h | ||
rtld_libc.c | ||
rtld_libc.h | ||
un-namespace.h |