enabled by default
disable using server.feature-flags += ("server.pcre_jit" => "disable")
Available since pcre-8.20 (2011), and improved in pcre-8.32 (2012),
PCRE_STUDY_JIT_COMPILE can greatly speed up repeated execution of PCRE
patterns. (https://zherczeg.github.io/sljit/pcre.html)
lighttpd continues to use pcre_exec() instead of pcre_jit_exec(),
even though doing so does not realize all of the performance increase
potentially available with PCRE_STUDY_JIT_COMPILE and pcre_jit_exec().
pcre_jit_exec() is available with PCRE 8.32 and later, if PCRE is
compiled with --enable-jit, but lighttpd does not currently use
pcre_jit_exec() since the PCRE library might not have been compiled
with --enable-jit (though this could be solved with a weak symbol).
Similarly, lighttpd does not currently configure the pcre_jit_stack.
(Using pcre_jit_exec() may be revisited in the future.)
x-ref:
"add support for pcre JIT"
https://redmine.lighttpd.net/issues/2361
Glenn Strauss