[llvm-dev] Slow debugger starts of LLVM tools

Shoaib Meenai via llvm-dev llvm-dev at lists.llvm.org
Wed Jan 9 14:48:08 PST 2019


I don't know about the issues with running being slow, but using a GDB index greatly speeds up initial symbol loading. Compile with `-ggnu-pubnames` and link with `-Xlinker --gdb-index` and you should get significantly faster symbol load times. (I'd be curious to see if it helps with the issues with run being slow as well.)

´╗┐On 1/9/19, 2:07 PM, "llvm-dev on behalf of David Greene via llvm-dev" <llvm-dev-bounces at lists.llvm.org on behalf of llvm-dev at lists.llvm.org> wrote:

    
    David Jones via llvm-dev <llvm-dev at lists.llvm.org> writes:
    
    > GDB likes to load all symbols from shared libraries up front. And on
    > x86_64 your main executable is really just another shared library.
    
    Yes, but does gdb reload everything on each execution?  Every time I
    execute "run" I see the same slow behavior.  Loading the symbols for
    small tools like llvm-rc takes hardly any time at all (i.e. "file
    llvm-rc" is almost instantaneous).  But executing it causes gdb to chew
    up CPU cycles for a while.  Every time.
    
                             -David
    _______________________________________________
    LLVM Developers mailing list
    llvm-dev at lists.llvm.org
    https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.llvm.org_cgi-2Dbin_mailman_listinfo_llvm-2Ddev&d=DwIGaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=o3kDXzdBUE3ljQXKeTWOMw&m=dqw6dQj2Nwimdo2WZ3P_n0WRZBWrrtNACdQfXzCB0Xc&s=psETNIS-WHrFqc7U8d3tg6i1UGx4-CHNUo0FO-FNQJg&e=
    



More information about the llvm-dev mailing list