brian.lu wrote: > Hi, experts, > > We met a problem when tuning firefox startup performance. The issue is: > NSPR shared library (which is used by Firefox) exports an interface (a > function name) to the applications (like Firefox). Applications can > provide a implementation of that function to override some > function provided by NSPR. Firefox doesn't use that interface. I.e. it > doesn't define that symbol. > > But every time, when firefox starts, NSPR lookups that symbol by using > dlsym(). That takes some time and fails finally. We can't modify the > NSPR codes > because it is not part of firefox code base. > Does ld.so.1 provide some mechanism that we can void looking up this > symbol in firefox?
Presumably you're referring to: 21799: 1: file=0; dlopen() called from file=/usr/lib/mps/libnspr4.so \ [ RTLD_LAZY RTLD_LOCAL RTLD_GROUP RTLD_WORLD ] ...... 21799: 1: symbol=nspr_use_zone_allocator; dlsym() called from \ file=/usr/lib/mps/libnspr4.so; starting at file=/usr/lib/firefox/firefox-bin ...... Which then looks for the symbol in every dependency that has so far been loaded, and then causes a bunch of pending lazy-loaded objects to be brought in in an attempt to find the symbol? And you can't change libnspr to either use dlopen(0, RTLD_FIRST), or use dlsym(RTLD_PROBE)? Could you not provide nspr_use_zone_allocator() as some null routine in firefox? Hmmm, the idea of defining a symbol within an object, and then tagging it in some way as "does-not-exist" such that a symbol lookup would be aborted when this symbol is found, is an idea to chew on :-) -- Rod.
