Tarrasch

\RequirePackage{filecontents}
\begin{filecontents}{bachelorarbeit_lit.bib}
@ONLINE{java96,
    author = {{Joe Black}},
    title = {Foobar 1.0},
    year = {1996},
    month = {1},
    url = {http://www.aaa.bb.cccc.dh/uploads/dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd.pdf},
    urldate = {2011-03-02},
    sortname = {Sun},

Tarrasch

I got this file by running:

❯ "inplace/bin/ghc-stage1" -optc-Wall -optc-Wextra -optc-Wstrict-prototypes -optc-Wmissing-prototypes -optc-Wmissing-declarations -optc-Winline -optc-Waggregate-return -optc-Wpointer-arith -optc-Wmissing-noreturn -optc-Wnested-externs -optc-Wredundant-decls -optc-Iincludes -optc-Iincludes/dist -optc-Iincludes/dist-derivedconstants/header -optc-Iincludes/dist-ghcconstants/header -optc-Irts -optc-Irts/dist/build -optc-DCOMPILING_RTS -optc-DDEBUG -optc-fno-strict-aliasing -optc-fno-common -optc-DUSE_DWARF -optc-O2 -optc-fomit-frame-pointer -optc-DRtsWay=\"rts_v\" -static  -O -H64m -Iincludes -Iincludes/dist -Iincludes/dist-derivedconstants/header -Iincludes/dist-ghcconstants/header -Irts -Irts/dist/build -DCOMPILING_RTS -package-name rts -dcmm-lint      -i -irts -irts/dist/build -irts/dist/build/autogen -Irts/dist/build -Irts/dist/build/autogen           -O2 -g    -c rts/sm/Scav.c -o rts/dist/build/sm/Scav.o


and then I ran:

objdump --source rts/dist/build/sm/Scav.o | less

And man

Tarrasch

Aw dammit they are still the same, why :(

Tarrasch

I ran

diff <(objdump --source Scav_explicit.o | sed 's:<.*>::') <(objdump --source Scav_use.o | sed 's:<.*>::') | xclip

where the sed part is for removing all the relative symbol names that changes. It was to eliminate garbage like this:

163c163
<      1f9:     73 55                   jae    250 <scavenge_stack+0x70>
---

Tarrasch

STATIC_INLINE StgPtr
scavenge_small_bitmap (StgPtr p, nat size, StgWord bitmap)
{
    while (size > 0) {
        if ((bitmap & 1) == 0) {
            evacuate((StgClosure **)p);
        }
        p++;
        bitmap = bitmap >> 1;
        size--;

Tarrasch

diff --git a/rts/sm/Compact.c b/rts/sm/Compact.c
index e9973d3..cdb487b 100644
--- a/rts/sm/Compact.c
+++ b/rts/sm/Compact.c
@@ -248,6 +248,20 @@ thread_large_bitmap( StgPtr p, StgLargeBitmap *large_bitmap, W_ size )
 }
 
 STATIC_INLINE StgPtr
+thread_small_bitmap (StgPtr p, nat size, StgWord bitmap)
+{

Tarrasch

{-# OPTIONS_GHC -w #-}
{-# OPTIONS -fglasgow-exts -cpp #-}
{-# LANGUAGE BangPatterns #-} -- required for versions of Happy before 1.18.6
{-# OPTIONS -Wwarn -w #-}
-- The above warning supression flag is a temporary kludge.
-- While working on this module you are encouraged to remove it and fix
-- any warnings in the module. See
--     http://ghc.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
-- for details

Tarrasch

In this little gist I will look at how it helps the debug data to use all the sections in the binary.

I will first compile the program with -g (using Peter's patches). Then I'll run it once and will get a quite nice stack trace. I will then succesively strip out important debug information and rerun the binary (without recompiling of course!). The result will be that the stack trace is degrading for each stripping, and we can then get a sense for the usefulness of each DWARF section in the binary.

Tarrasch

import datetime
import luigi
from spotify.luigi.crunch import ScrubJobTask, load_avsc
from spotify.luigi import HdfsTarget
from spotify.luigi.external_shrek_anonym import CreateEndSongCleaned


class SampleEndSongSubset(luigi.ExternalTask):
    def output(self):
        return HdfsTarget("/user/spotify-analytics-data/examples/data_pipeline_crunch/stream_count_anonym")

Tarrasch

~/spotify/repos/gcp-migrate various-improvements  
❯ git remote -v
origin	git@ghe.spotify.net:arash/gcp-migrate.git (fetch)
origin	git@ghe.spotify.net:arash/gcp-migrate.git (push)
upstream	https://ghe.spotify.net/datainfra/gcp-migrate.git (fetch)
upstream	https://ghe.spotify.net/datainfra/gcp-migrate.git (push)
                                                                                                                                                                                                                                                                                            
~/spotify/repos/gcp-migrate various-improvements  
❯ git fetch --all
Fetching origin