Memory Profiling

Introduction

Tools

  • Valgrind
    • Massif - Heap profiling

    • DHAT - Dynamic Heap Analysis Tool (experimental)

  • IgProf

  • Heaptrack

  • Deep Memory Profiler

Current Version

Valgrind

3.10.1

Valgrind

  • Bug Reports
    • KDE 讓 Valgrind 可以使用他們的 Bugzilla

  • irc : freenode #valgrind-dev

架構

Valgrind 的 command 其實只是個 wrapper (wrapper 的 source code 為 repo 裡的 coregrind/launcher-linux.c), 每個 plugin 都是一個執行檔, plugin 都放在 /usr/lib/valgrind/ 裡面 (on Arch Linux), command 會設定一些環境變數後執行指定的 plugin。

Valgrind 內部有 VEX IR (RISC-like), 會先把要跑的 binary 轉成內部的 VEX IR, 在這之上做處理, 底下再用 Virtual Machine 轉回去 Host Machine 的指令集來執行。

Valgrind 的每個 plugin 都是依照 Valgrind 提供的 framework 來撰寫, 最後整個 link 成執行檔。

執行的大概狀況 (待補資訊)::

    /usr/bin/valgrind --tool=XXX ./myprogram
=>  execve /usr/lib/valgrind/XXX-amd64-linux ...
=>  open myprogram
=>  load preload /usr/lib/valgrind/vgpreload_XXX-amd64-linux.so
=>  other tool's stuff

Installation

command:

$ pacman -S valgrind    # Arch Linux

files:

$ pacman -Ql valgrind   # Arch Linux

Valgrind’s files (install on Arch Linux):

valgrind /usr/
valgrind /usr/bin/
valgrind /usr/bin/callgrind_annotate
valgrind /usr/bin/callgrind_control
valgrind /usr/bin/cg_annotate
valgrind /usr/bin/cg_diff
valgrind /usr/bin/cg_merge
valgrind /usr/bin/ms_print
valgrind /usr/bin/valgrind
valgrind /usr/bin/valgrind-di-server
valgrind /usr/bin/valgrind-listener
valgrind /usr/bin/vgdb
valgrind /usr/include/
valgrind /usr/include/valgrind/
valgrind /usr/include/valgrind/callgrind.h
valgrind /usr/include/valgrind/config.h
valgrind /usr/include/valgrind/drd.h
valgrind /usr/include/valgrind/helgrind.h
valgrind /usr/include/valgrind/libvex.h
valgrind /usr/include/valgrind/libvex_basictypes.h
valgrind /usr/include/valgrind/libvex_emnote.h
valgrind /usr/include/valgrind/libvex_guest_amd64.h
valgrind /usr/include/valgrind/libvex_guest_arm.h
valgrind /usr/include/valgrind/libvex_guest_arm64.h
valgrind /usr/include/valgrind/libvex_guest_mips32.h
valgrind /usr/include/valgrind/libvex_guest_mips64.h
valgrind /usr/include/valgrind/libvex_guest_offsets.h
valgrind /usr/include/valgrind/libvex_guest_ppc32.h
valgrind /usr/include/valgrind/libvex_guest_ppc64.h
valgrind /usr/include/valgrind/libvex_guest_s390x.h
valgrind /usr/include/valgrind/libvex_guest_x86.h
valgrind /usr/include/valgrind/libvex_ir.h
valgrind /usr/include/valgrind/libvex_s390x_common.h
valgrind /usr/include/valgrind/libvex_trc_values.h
valgrind /usr/include/valgrind/memcheck.h
valgrind /usr/include/valgrind/pub_tool_addrinfo.h
valgrind /usr/include/valgrind/pub_tool_aspacehl.h
valgrind /usr/include/valgrind/pub_tool_aspacemgr.h
valgrind /usr/include/valgrind/pub_tool_basics.h
valgrind /usr/include/valgrind/pub_tool_basics_asm.h
valgrind /usr/include/valgrind/pub_tool_clientstate.h
valgrind /usr/include/valgrind/pub_tool_clreq.h
valgrind /usr/include/valgrind/pub_tool_debuginfo.h
valgrind /usr/include/valgrind/pub_tool_deduppoolalloc.h
valgrind /usr/include/valgrind/pub_tool_errormgr.h
valgrind /usr/include/valgrind/pub_tool_execontext.h
valgrind /usr/include/valgrind/pub_tool_gdbserver.h
valgrind /usr/include/valgrind/pub_tool_hashtable.h
valgrind /usr/include/valgrind/pub_tool_libcassert.h
valgrind /usr/include/valgrind/pub_tool_libcbase.h
valgrind /usr/include/valgrind/pub_tool_libcfile.h
valgrind /usr/include/valgrind/pub_tool_libcprint.h
valgrind /usr/include/valgrind/pub_tool_libcproc.h
valgrind /usr/include/valgrind/pub_tool_libcsetjmp.h
valgrind /usr/include/valgrind/pub_tool_libcsignal.h
valgrind /usr/include/valgrind/pub_tool_machine.h
valgrind /usr/include/valgrind/pub_tool_mallocfree.h
valgrind /usr/include/valgrind/pub_tool_options.h
valgrind /usr/include/valgrind/pub_tool_oset.h
valgrind /usr/include/valgrind/pub_tool_poolalloc.h
valgrind /usr/include/valgrind/pub_tool_rangemap.h
valgrind /usr/include/valgrind/pub_tool_redir.h
valgrind /usr/include/valgrind/pub_tool_replacemalloc.h
valgrind /usr/include/valgrind/pub_tool_seqmatch.h
valgrind /usr/include/valgrind/pub_tool_signals.h
valgrind /usr/include/valgrind/pub_tool_sparsewa.h
valgrind /usr/include/valgrind/pub_tool_stacktrace.h
valgrind /usr/include/valgrind/pub_tool_threadstate.h
valgrind /usr/include/valgrind/pub_tool_tooliface.h
valgrind /usr/include/valgrind/pub_tool_vki.h
valgrind /usr/include/valgrind/pub_tool_vkiscnums.h
valgrind /usr/include/valgrind/pub_tool_vkiscnums_asm.h
valgrind /usr/include/valgrind/pub_tool_wordfm.h
valgrind /usr/include/valgrind/pub_tool_xarray.h
valgrind /usr/include/valgrind/valgrind.h
valgrind /usr/include/valgrind/vki/
valgrind /usr/include/valgrind/vki/vki-amd64-linux.h
valgrind /usr/include/valgrind/vki/vki-arm-linux.h
valgrind /usr/include/valgrind/vki/vki-arm64-linux.h
valgrind /usr/include/valgrind/vki/vki-darwin.h
valgrind /usr/include/valgrind/vki/vki-linux-drm.h
valgrind /usr/include/valgrind/vki/vki-linux.h
valgrind /usr/include/valgrind/vki/vki-mips32-linux.h
valgrind /usr/include/valgrind/vki/vki-mips64-linux.h
valgrind /usr/include/valgrind/vki/vki-posixtypes-amd64-linux.h
valgrind /usr/include/valgrind/vki/vki-posixtypes-arm-linux.h
valgrind /usr/include/valgrind/vki/vki-posixtypes-arm64-linux.h
valgrind /usr/include/valgrind/vki/vki-posixtypes-mips32-linux.h
valgrind /usr/include/valgrind/vki/vki-posixtypes-mips64-linux.h
valgrind /usr/include/valgrind/vki/vki-posixtypes-ppc32-linux.h
valgrind /usr/include/valgrind/vki/vki-posixtypes-ppc64-linux.h
valgrind /usr/include/valgrind/vki/vki-posixtypes-s390x-linux.h
valgrind /usr/include/valgrind/vki/vki-posixtypes-x86-linux.h
valgrind /usr/include/valgrind/vki/vki-ppc32-linux.h
valgrind /usr/include/valgrind/vki/vki-ppc64-linux.h
valgrind /usr/include/valgrind/vki/vki-s390x-linux.h
valgrind /usr/include/valgrind/vki/vki-scnums-amd64-linux.h
valgrind /usr/include/valgrind/vki/vki-scnums-arm-linux.h
valgrind /usr/include/valgrind/vki/vki-scnums-arm64-linux.h
valgrind /usr/include/valgrind/vki/vki-scnums-darwin.h
valgrind /usr/include/valgrind/vki/vki-scnums-mips32-linux.h
valgrind /usr/include/valgrind/vki/vki-scnums-mips64-linux.h
valgrind /usr/include/valgrind/vki/vki-scnums-ppc32-linux.h
valgrind /usr/include/valgrind/vki/vki-scnums-ppc64-linux.h
valgrind /usr/include/valgrind/vki/vki-scnums-s390x-linux.h
valgrind /usr/include/valgrind/vki/vki-scnums-x86-linux.h
valgrind /usr/include/valgrind/vki/vki-x86-linux.h
valgrind /usr/include/valgrind/vki/vki-xen-domctl.h
valgrind /usr/include/valgrind/vki/vki-xen-evtchn.h
valgrind /usr/include/valgrind/vki/vki-xen-gnttab.h
valgrind /usr/include/valgrind/vki/vki-xen-hvm.h
valgrind /usr/include/valgrind/vki/vki-xen-memory.h
valgrind /usr/include/valgrind/vki/vki-xen-mmuext.h
valgrind /usr/include/valgrind/vki/vki-xen-sysctl.h
valgrind /usr/include/valgrind/vki/vki-xen-tmem.h
valgrind /usr/include/valgrind/vki/vki-xen-version.h
valgrind /usr/include/valgrind/vki/vki-xen-x86.h
valgrind /usr/include/valgrind/vki/vki-xen.h
valgrind /usr/lib/
valgrind /usr/lib/pkgconfig/
valgrind /usr/lib/pkgconfig/valgrind.pc
valgrind /usr/lib/valgrind/
valgrind /usr/lib/valgrind/32bit-core-valgrind-s1.xml
valgrind /usr/lib/valgrind/32bit-core-valgrind-s2.xml
valgrind /usr/lib/valgrind/32bit-core.xml
valgrind /usr/lib/valgrind/32bit-linux-valgrind-s1.xml
valgrind /usr/lib/valgrind/32bit-linux-valgrind-s2.xml
valgrind /usr/lib/valgrind/32bit-linux.xml
valgrind /usr/lib/valgrind/32bit-sse-valgrind-s1.xml
valgrind /usr/lib/valgrind/32bit-sse-valgrind-s2.xml
valgrind /usr/lib/valgrind/32bit-sse.xml
valgrind /usr/lib/valgrind/64bit-avx-valgrind-s1.xml
valgrind /usr/lib/valgrind/64bit-avx-valgrind-s2.xml
valgrind /usr/lib/valgrind/64bit-avx.xml
valgrind /usr/lib/valgrind/64bit-core-valgrind-s1.xml
valgrind /usr/lib/valgrind/64bit-core-valgrind-s2.xml
valgrind /usr/lib/valgrind/64bit-core.xml
valgrind /usr/lib/valgrind/64bit-linux-valgrind-s1.xml
valgrind /usr/lib/valgrind/64bit-linux-valgrind-s2.xml
valgrind /usr/lib/valgrind/64bit-linux.xml
valgrind /usr/lib/valgrind/64bit-sse-valgrind-s1.xml
valgrind /usr/lib/valgrind/64bit-sse-valgrind-s2.xml
valgrind /usr/lib/valgrind/64bit-sse.xml
valgrind /usr/lib/valgrind/amd64-avx-coresse-valgrind.xml
valgrind /usr/lib/valgrind/amd64-avx-coresse.xml
valgrind /usr/lib/valgrind/amd64-avx-linux-valgrind.xml
valgrind /usr/lib/valgrind/amd64-avx-linux.xml
valgrind /usr/lib/valgrind/amd64-coresse-valgrind.xml
valgrind /usr/lib/valgrind/amd64-linux-valgrind.xml
valgrind /usr/lib/valgrind/arm-core-valgrind-s1.xml
valgrind /usr/lib/valgrind/arm-core-valgrind-s2.xml
valgrind /usr/lib/valgrind/arm-core.xml
valgrind /usr/lib/valgrind/arm-vfpv3-valgrind-s1.xml
valgrind /usr/lib/valgrind/arm-vfpv3-valgrind-s2.xml
valgrind /usr/lib/valgrind/arm-vfpv3.xml
valgrind /usr/lib/valgrind/arm-with-vfpv3-valgrind.xml
valgrind /usr/lib/valgrind/arm-with-vfpv3.xml
valgrind /usr/lib/valgrind/cachegrind-amd64-linux
valgrind /usr/lib/valgrind/callgrind-amd64-linux
valgrind /usr/lib/valgrind/default.supp
valgrind /usr/lib/valgrind/drd-amd64-linux
valgrind /usr/lib/valgrind/exp-bbv-amd64-linux
valgrind /usr/lib/valgrind/exp-dhat-amd64-linux
valgrind /usr/lib/valgrind/exp-sgcheck-amd64-linux
valgrind /usr/lib/valgrind/getoff-amd64-linux
valgrind /usr/lib/valgrind/helgrind-amd64-linux
valgrind /usr/lib/valgrind/i386-coresse-valgrind.xml
valgrind /usr/lib/valgrind/i386-linux-valgrind.xml
valgrind /usr/lib/valgrind/lackey-amd64-linux
valgrind /usr/lib/valgrind/libcoregrind-amd64-linux.a
valgrind /usr/lib/valgrind/libmpiwrap-amd64-linux.so
valgrind /usr/lib/valgrind/libreplacemalloc_toolpreload-amd64-linux.a
valgrind /usr/lib/valgrind/libvex-amd64-linux.a
valgrind /usr/lib/valgrind/massif-amd64-linux
valgrind /usr/lib/valgrind/memcheck-amd64-linux
valgrind /usr/lib/valgrind/mips-cp0-valgrind-s1.xml
valgrind /usr/lib/valgrind/mips-cp0-valgrind-s2.xml
valgrind /usr/lib/valgrind/mips-cp0.xml
valgrind /usr/lib/valgrind/mips-cpu-valgrind-s1.xml
valgrind /usr/lib/valgrind/mips-cpu-valgrind-s2.xml
valgrind /usr/lib/valgrind/mips-cpu.xml
valgrind /usr/lib/valgrind/mips-fpu-valgrind-s1.xml
valgrind /usr/lib/valgrind/mips-fpu-valgrind-s2.xml
valgrind /usr/lib/valgrind/mips-fpu.xml
valgrind /usr/lib/valgrind/mips-linux-valgrind.xml
valgrind /usr/lib/valgrind/mips-linux.xml
valgrind /usr/lib/valgrind/mips64-cp0-valgrind-s1.xml
valgrind /usr/lib/valgrind/mips64-cp0-valgrind-s2.xml
valgrind /usr/lib/valgrind/mips64-cp0.xml
valgrind /usr/lib/valgrind/mips64-cpu-valgrind-s1.xml
valgrind /usr/lib/valgrind/mips64-cpu-valgrind-s2.xml
valgrind /usr/lib/valgrind/mips64-cpu.xml
valgrind /usr/lib/valgrind/mips64-fpu-valgrind-s1.xml
valgrind /usr/lib/valgrind/mips64-fpu-valgrind-s2.xml
valgrind /usr/lib/valgrind/mips64-fpu.xml
valgrind /usr/lib/valgrind/mips64-linux-valgrind.xml
valgrind /usr/lib/valgrind/mips64-linux.xml
valgrind /usr/lib/valgrind/none-amd64-linux
valgrind /usr/lib/valgrind/power-altivec-valgrind-s1.xml
valgrind /usr/lib/valgrind/power-altivec-valgrind-s2.xml
valgrind /usr/lib/valgrind/power-altivec.xml
valgrind /usr/lib/valgrind/power-core-valgrind-s1.xml
valgrind /usr/lib/valgrind/power-core-valgrind-s2.xml
valgrind /usr/lib/valgrind/power-core.xml
valgrind /usr/lib/valgrind/power-fpu-valgrind-s1.xml
valgrind /usr/lib/valgrind/power-fpu-valgrind-s2.xml
valgrind /usr/lib/valgrind/power-fpu.xml
valgrind /usr/lib/valgrind/power-linux-valgrind-s1.xml
valgrind /usr/lib/valgrind/power-linux-valgrind-s2.xml
valgrind /usr/lib/valgrind/power-linux.xml
valgrind /usr/lib/valgrind/power64-core-valgrind-s1.xml
valgrind /usr/lib/valgrind/power64-core-valgrind-s2.xml
valgrind /usr/lib/valgrind/power64-core.xml
valgrind /usr/lib/valgrind/power64-linux-valgrind-s1.xml
valgrind /usr/lib/valgrind/power64-linux-valgrind-s2.xml
valgrind /usr/lib/valgrind/power64-linux.xml
valgrind /usr/lib/valgrind/powerpc-altivec32l-valgrind.xml
valgrind /usr/lib/valgrind/powerpc-altivec32l.xml
valgrind /usr/lib/valgrind/powerpc-altivec64l-valgrind.xml
valgrind /usr/lib/valgrind/powerpc-altivec64l.xml
valgrind /usr/lib/valgrind/s390-acr-valgrind-s1.xml
valgrind /usr/lib/valgrind/s390-acr-valgrind-s2.xml
valgrind /usr/lib/valgrind/s390-acr.xml
valgrind /usr/lib/valgrind/s390-fpr-valgrind-s1.xml
valgrind /usr/lib/valgrind/s390-fpr-valgrind-s2.xml
valgrind /usr/lib/valgrind/s390-fpr.xml
valgrind /usr/lib/valgrind/s390x-core64-valgrind-s1.xml
valgrind /usr/lib/valgrind/s390x-core64-valgrind-s2.xml
valgrind /usr/lib/valgrind/s390x-core64.xml
valgrind /usr/lib/valgrind/s390x-generic-valgrind.xml
valgrind /usr/lib/valgrind/s390x-generic.xml
valgrind /usr/lib/valgrind/s390x-linux64-valgrind-s1.xml
valgrind /usr/lib/valgrind/s390x-linux64-valgrind-s2.xml
valgrind /usr/lib/valgrind/s390x-linux64.xml
valgrind /usr/lib/valgrind/vgpreload_core-amd64-linux.so
valgrind /usr/lib/valgrind/vgpreload_drd-amd64-linux.so
valgrind /usr/lib/valgrind/vgpreload_exp-dhat-amd64-linux.so
valgrind /usr/lib/valgrind/vgpreload_exp-sgcheck-amd64-linux.so
valgrind /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so
valgrind /usr/lib/valgrind/vgpreload_massif-amd64-linux.so
valgrind /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so
valgrind /usr/share/
valgrind /usr/share/doc/
valgrind /usr/share/doc/valgrind/
valgrind /usr/share/doc/valgrind/html/
valgrind /usr/share/doc/valgrind/html/FAQ.html
valgrind /usr/share/doc/valgrind/html/QuickStart.html
valgrind /usr/share/doc/valgrind/html/bbv-manual.html
valgrind /usr/share/doc/valgrind/html/cg-manual.html
valgrind /usr/share/doc/valgrind/html/cl-format.html
valgrind /usr/share/doc/valgrind/html/cl-manual.html
valgrind /usr/share/doc/valgrind/html/design-impl.html
valgrind /usr/share/doc/valgrind/html/dh-manual.html
valgrind /usr/share/doc/valgrind/html/dist.authors.html
valgrind /usr/share/doc/valgrind/html/dist.html
valgrind /usr/share/doc/valgrind/html/dist.news.html
valgrind /usr/share/doc/valgrind/html/dist.news.old.html
valgrind /usr/share/doc/valgrind/html/dist.readme-android.html
valgrind /usr/share/doc/valgrind/html/dist.readme-android_emulator.html
valgrind /usr/share/doc/valgrind/html/dist.readme-developers.html
valgrind /usr/share/doc/valgrind/html/dist.readme-mips.html
valgrind /usr/share/doc/valgrind/html/dist.readme-missing.html
valgrind /usr/share/doc/valgrind/html/dist.readme-packagers.html
valgrind /usr/share/doc/valgrind/html/dist.readme-s390.html
valgrind /usr/share/doc/valgrind/html/dist.readme.html
valgrind /usr/share/doc/valgrind/html/drd-manual.html
valgrind /usr/share/doc/valgrind/html/faq.html
valgrind /usr/share/doc/valgrind/html/hg-manual.html
valgrind /usr/share/doc/valgrind/html/images/
valgrind /usr/share/doc/valgrind/html/images/home.png
valgrind /usr/share/doc/valgrind/html/images/next.png
valgrind /usr/share/doc/valgrind/html/images/prev.png
valgrind /usr/share/doc/valgrind/html/images/up.png
valgrind /usr/share/doc/valgrind/html/index.html
valgrind /usr/share/doc/valgrind/html/license.gfdl.html
valgrind /usr/share/doc/valgrind/html/license.gpl.html
valgrind /usr/share/doc/valgrind/html/licenses.html
valgrind /usr/share/doc/valgrind/html/lk-manual.html
valgrind /usr/share/doc/valgrind/html/manual-core-adv.html
valgrind /usr/share/doc/valgrind/html/manual-core.html
valgrind /usr/share/doc/valgrind/html/manual-intro.html
valgrind /usr/share/doc/valgrind/html/manual-writing-tools.html
valgrind /usr/share/doc/valgrind/html/manual.html
valgrind /usr/share/doc/valgrind/html/mc-manual.html
valgrind /usr/share/doc/valgrind/html/ms-manual.html
valgrind /usr/share/doc/valgrind/html/nl-manual.html
valgrind /usr/share/doc/valgrind/html/quick-start.html
valgrind /usr/share/doc/valgrind/html/sg-manual.html
valgrind /usr/share/doc/valgrind/html/tech-docs.html
valgrind /usr/share/doc/valgrind/html/vg_basic.css
valgrind /usr/share/doc/valgrind/valgrind_manual.pdf
valgrind /usr/share/doc/valgrind/valgrind_manual.ps
valgrind /usr/share/man/
valgrind /usr/share/man/man1/
valgrind /usr/share/man/man1/callgrind_annotate.1.gz
valgrind /usr/share/man/man1/callgrind_control.1.gz
valgrind /usr/share/man/man1/cg_annotate.1.gz
valgrind /usr/share/man/man1/cg_diff.1.gz
valgrind /usr/share/man/man1/cg_merge.1.gz
valgrind /usr/share/man/man1/ms_print.1.gz
valgrind /usr/share/man/man1/valgrind-listener.1.gz
valgrind /usr/share/man/man1/valgrind.1.gz
valgrind /usr/share/man/man1/vgdb.1.gz

Valgrind Plugins

Valgrind - Massif

Massif 是一個 heap profiler, 利用定期對程式的 heap 做 snapshots 來做 profiling, 分析 heap 的使用量,以及多少的記憶體是為了 book-keeping 或是 alignment 而花費掉的, 也可以測量 stack 的使用量 (預設沒開), 最後產生出 graph 來呈現 heap 在各個時間點的使用量, 並且包含程式的哪部份用了最多的 memory allocations, 圖可以在 terminal 上直接呈現, 但是執行 Massif 會讓程式慢大約 20 倍。

每次 heap 做 allocation 或是 deallocation 的時候 Massif 就會做 snapshot, 預設最多保留 100 個 snapshot,但是可以用 --max-snapshots 參數來調整, 大部分的 snapshot 為 normal snapshot (只紀錄基本的資訊), 這種 snapshot 在圖上會用 : 來表示, 少部份為 detailed snapshot (會包含更多資訊), 這種 snapshot 在圖上會用 @ 來表示, 最後還有一種叫作 peak snapshot, peak snapshot 是 detailed snapshot 的一種, 但是是記憶體使用量最高的地方, 這種 snapshot 在圖上會用 # 來表示。

Massif 預設是紀錄透過 malloc、calloc、realloc、memalign、new、new[] 等等 function 來取得的記憶體, 而不是更低階的 mmap、mremap、brk system call, 也不會紀錄其他區塊的大小 (例如 code、data、BSS segments), 但是可以用 --pages-as-heap=yes 參數來把所有的 memory pages 都紀錄起來 (當然包含 stack)

編譯你的程式的時候當然最好使用 -g 來加上 debug info 再來執行, 這樣可以取得更多資訊。

Massif 的執行結果預設會寫到叫作 massif.out.<pid> 的檔案, 可以用 --massif-out-file 參數來更改。

使用參數:

  • --tool=massif : 選擇使用 massif

  • --stacks=yes : 也紀錄 stack 的使用量

生出的結果可以用 ms_print 指令來觀看, 例如:

$ ms_print massif.out.18904
--------------------------------------------------------------------------------
Command:            ./a.out
Massif arguments:   --time-unit=B
ms_print arguments: massif.out.18904
--------------------------------------------------------------------------------


     B
  120^                                    ###################################
     |                                    #
     |                                    #
     |                                    #
     |                                    #
     |                                    #
     |                                    #
     |                                    #
     |                                    #
     |                                    #
     |                                    #
     |                                    #
     |                                    #
     |                                    #
     |                                    #
     |                                    #
     |                                    #
     |                                    #
     |                                    #
     |                                    #
   0 +----------------------------------------------------------------------->B
     0                                                                     240

Number of snapshots: 4
 Detailed snapshots: [2 (peak)]

--------------------------------------------------------------------------------
  n        time(B)         total(B)   useful-heap(B) extra-heap(B)    stacks(B)
--------------------------------------------------------------------------------
  0              0                0                0             0            0
  1            120              120              100            20            0
  2            120              120              100            20            0
83.33% (100B) (heap allocation functions) malloc/new/new[], --alloc-fns, etc.
->83.33% (100B) 0x400556: main (single-heap-more-char.c:4)

--------------------------------------------------------------------------------
  n        time(B)         total(B)   useful-heap(B) extra-heap(B)    stacks(B)
--------------------------------------------------------------------------------
  3            240                0                0             0            0
$ ms_print massif.out.18829
--------------------------------------------------------------------------------
Command:            ./a.out
Massif arguments:   --stacks=yes
ms_print arguments: massif.out.18868
--------------------------------------------------------------------------------


    KB
3.125^         ##
     |         # @
     |         # @
     |      :  # @
     |      :  # @
     |    : : :# @
     |    : : :# @
     |    : : :# @
     |    ::: :# @
     |    ::: :# @
     |    ::: :# @
     |    ::: :# @             : :: ::::  : :   :            ::       ::    @
     |    ::: :# @             : :: : ::  : :   :            ::  : :  ::    @
     |    ::: :# @             : :::: ::: :::@ ::::::  :@ : ::: ::@:::::  : @
     |    :::::# @             :::::: :::::::@::::::::::@:: ::: ::@:::::  : @
     |    :::::# @ :         :::::::: :::::::@::::::::::@::::@::::@::::@  : @
     |  : :::::# @::::::::::::::::::: :::::::@::::::::::@::::@::::@::::@::: @
     | ::::::::# @:::        :::::::: :::::::@::::::::::@::::@::::@::::@::::@
     |:::::::::# @:::        :::::::: :::::::@::::::::::@::::@::::@::::@::::@:
     |:::::::::# @:::        :::::::: :::::::@::::::::::@::::@::::@::::@::::@:
   0 +----------------------------------------------------------------------->ki
     0                                                                   124.6

Number of snapshots: 92
 Detailed snapshots: [12 (peak), 13, 14, 36, 47, 57, 67, 77, 87]

--------------------------------------------------------------------------------
  n        time(i)         total(B)   useful-heap(B) extra-heap(B)    stacks(B)
--------------------------------------------------------------------------------
  0              0                0                0             0            0
  1          1,492              472                0             0          472
  2          3,046              584                0             0          584
  3          4,046              752                0             0          752
  4          5,748              592                0             0          592
  5          7,178            2,472                0             0        2,472
  6          8,346              600                0             0          600
  7         10,002            2,048                0             0        2,048
  8         11,537            2,720                0             0        2,720
  9         12,774            1,008                0             0        1,008
 10         14,855            2,448                0             0        2,448
 11         16,354            2,496                0             0        2,496
 12         17,461            3,200                0             0        3,200
00.00% (0B) (heap allocation functions) malloc/new/new[], --alloc-fns, etc.

...

--------------------------------------------------------------------------------
  n        time(i)         total(B)   useful-heap(B) extra-heap(B)    stacks(B)
--------------------------------------------------------------------------------
 78        117,027              280                0             0          280
 79        117,910              280                0             0          280
 80        118,710              744                0             0          744
 81        119,512              400                0             0          400
 82        120,315              704                0             0          704
 83        121,182            1,160              100            20        1,040
 84        121,999              664                0             0          664
 85        122,815              456                0             0          456
 86        123,628              520                0             0          520
 87        124,428            1,440                0             0        1,440
00.00% (0B) (heap allocation functions) malloc/new/new[], --alloc-fns, etc.
...
$ ms_print massif.out.21469
--------------------------------------------------------------------------------
Command:            ./a.out
Massif arguments:   --time-unit=B --pages-as-heap=yes
ms_print arguments: massif.out.21469
--------------------------------------------------------------------------------


    MB
5.996^                                                                       :
     |                                                                    ::#:
     |                                                                    ::#:
     |                                                                    ::#:
     |                                                                    ::#:
     |                                                                    ::#:
     |                                                                    ::#:
     |                                                                    ::#:
     |                                                                    ::#:
     |                                                                    ::#:
     |                                                                    ::#:
     |                                                                    ::#:
     |                                                                    ::#:
     |                         :::::::::::::::::::::::::::::::::::::::::::::#:
     |                         ::                                         ::#:
     |                         ::                                         ::#:
     |                         ::                                         ::#:
     |                         ::                                         ::#:
     |                         ::                                         ::#:
     |                         ::                                         ::#:
   0 +----------------------------------------------------------------------->MB
     0                                                                   6.230

Number of snapshots: 21
 Detailed snapshots: [9, 18 (peak)]

--------------------------------------------------------------------------------
  n        time(B)         total(B)   useful-heap(B) extra-heap(B)    stacks(B)
--------------------------------------------------------------------------------
  0          4,096            4,096            4,096             0            0
  1          8,192            8,192            8,192             0            0
  2        147,456          147,456          147,456             0            0
  3        155,648          155,648          155,648             0            0
  4        159,744          159,744          159,744             0            0
  5        163,840          163,840          163,840             0            0
  6        167,936          167,936          167,936             0            0
  7        176,128          176,128          176,128             0            0
  8        180,224          180,224          180,224             0            0
  9        180,224          180,224          180,224             0            0
100.00% (180,224B) (page allocation syscalls) mmap/mremap/brk, --alloc-fns, etc.
->100.00% (180,224B) 0xFFFFFFFFFFFFFFFF: ???

--------------------------------------------------------------------------------
  n        time(B)         total(B)   useful-heap(B) extra-heap(B)    stacks(B)
--------------------------------------------------------------------------------
 10      2,285,568        2,285,568        2,285,568             0            0
 11      2,293,760        2,293,760        2,293,760             0            0
 12      2,416,640        2,416,640        2,416,640             0            0
 13      2,420,736        2,420,736        2,420,736             0            0
 14      6,230,016        6,230,016        6,230,016             0            0
 15      6,254,592        6,254,592        6,254,592             0            0
 16      6,270,976        6,270,976        6,270,976             0            0
 17      6,275,072        6,275,072        6,275,072             0            0
 18      6,393,856        6,156,288        6,156,288             0            0
100.00% (6,156,288B) (page allocation syscalls) mmap/mremap/brk, --alloc-fns, etc.
->97.07% (5,976,064B) 0x40183A9: mmap (in /usr/lib/ld-2.21.so)
| ->96.07% (5,914,624B) 0x40065CE: _dl_map_object_from_fd (in /usr/lib/ld-2.21.so)
| | ->96.07% (5,914,624B) 0x4008544: _dl_map_object (in /usr/lib/ld-2.21.so)
| |   ->61.88% (3,809,280B) 0x400CA60: openaux (in /usr/lib/ld-2.21.so)
| |   | ->61.88% (3,809,280B) 0x400EF92: _dl_catch_error (in /usr/lib/ld-2.21.so)
| |   |   ->61.88% (3,809,280B) 0x400CCC2: _dl_map_object_deps (in /usr/lib/ld-2.21.so)
| |   |     ->61.88% (3,809,280B) 0x400304C: dl_main (in /usr/lib/ld-2.21.so)
| |   |       ->61.88% (3,809,280B) 0x401643E: _dl_sysdep_start (in /usr/lib/ld-2.21.so)
| |   |         ->61.88% (3,809,280B) 0x4004D88: _dl_start (in /usr/lib/ld-2.21.so)
| |   |           ->61.88% (3,809,280B) 0x4000D86: ??? (in /usr/lib/ld-2.21.so)
| |   |
| |   ->34.20% (2,105,344B) 0x4000F63: map_doit (in /usr/lib/ld-2.21.so)
| |     ->34.20% (2,105,344B) 0x400EF92: _dl_catch_error (in /usr/lib/ld-2.21.so)
| |       ->34.20% (2,105,344B) 0x4000BCD: do_preload (in /usr/lib/ld-2.21.so)
| |         ->34.20% (2,105,344B) 0x4003580: dl_main (in /usr/lib/ld-2.21.so)
| |           ->34.20% (2,105,344B) 0x401643E: _dl_sysdep_start (in /usr/lib/ld-2.21.so)
| |             ->34.20% (2,105,344B) 0x4004D88: _dl_start (in /usr/lib/ld-2.21.so)
| |               ->34.20% (2,105,344B) 0x4000D86: ??? (in /usr/lib/ld-2.21.so)
| |
| ->01.00% (61,440B) in 1+ places, all below ms_print's threshold (01.00%)
|
->02.93% (180,224B) 0xFFFFFFFFFFFFFFFF: ???

--------------------------------------------------------------------------------
  n        time(B)         total(B)   useful-heap(B) extra-heap(B)    stacks(B)
--------------------------------------------------------------------------------
 19      6,397,952        6,152,192        6,152,192             0            0
 20      6,533,120        6,287,360        6,287,360             0            0

Valgrind - DHAT

DHAT 是用來檢查程式如何使用 heap 的工具, 會紀錄 allocate 的記憶體、每個記憶體存取 (找哪一塊記憶體) 等等。

使用參數:

  • --tool=exp-dhat : 選擇使用 massif

code:

// C

#include <stdlib.h>

int main () {
    // allocate a lot of heap memory, and then free without using it
    // and here may pay some heap memory for memory allocator
    char* c = malloc(sizeof(char) * 100);
    c[0] = 'a';
    c[7] = 'z';
    free(c);
    return 0;
}

Valgrind:

$ valgrind --tool=exp-dhat ./single-heap-more-char
==2607== DHAT, a dynamic heap analysis tool
==2607== NOTE: This is an Experimental-Class Valgrind Tool
==2607== Copyright (C) 2010-2013, and GNU GPL'd, by Mozilla Inc
==2607== Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright info
==2607== Command: ./single-heap-more-char
==2607==
==2607==
==2607== ======== SUMMARY STATISTICS ========
==2607==
==2607== guest_insns:  127,901
==2607==
==2607== max_live:     100 in 1 blocks
==2607==
==2607== tot_alloc:    100 in 1 blocks
==2607==
==2607== insns per allocated byte: 1,279
==2607==
==2607==
==2607== ======== ORDERED BY decreasing "max-bytes-live": top 10 allocators ========
==2607==
==2607== -------------------- 1 of 10 --------------------
==2607== max-live:    100 in 1 blocks
==2607== tot-alloc:   100 in 1 blocks (avg size 100.00)
==2607== deaths:      1, at avg age 912 (0.71% of prog lifetime)
==2607== acc-ratios:  0.00 rd, 0.02 wr  (0 b-read, 2 b-written)
==2607==    at 0x4C280B0: malloc (in /usr/lib/valgrind/vgpreload_exp-dhat-amd64-linux.so)
==2607==    by 0x400557: main (single-heap-more-char.c:6)
==2607==
==2607== Aggregated access counts by offset:
==2607==
==2607== [   0]  1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0
==2607== [  16]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==2607== [  32]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==2607== [  48]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==2607== [  64]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==2607== [  80]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==2607== [  96]  0 0 0 0
==2607==
==2607==
==2607==
==2607== ==============================================================
==2607==
==2607== Some hints: (see --help for command line option details):
==2607==
==2607== * summary stats for whole program are at the top of this output
==2607==
==2607== * --show-top-n=  controls how many alloc points are shown.
==2607==                  You probably want to set it much higher than
==2607==                  the default value (10)
==2607==
==2607== * --sort-by=     specifies the sort key for output.
==2607==                  See --help for details.
==2607==
==2607== * Each allocation stack, by default 12 frames, counts as
==2607==   a separate alloc point.  This causes the data to be spread out
==2607==   over far too many alloc points.  I strongly suggest using
==2607==   --num-callers=4 or some such, to reduce the spreading.
==2607==

Valgrind - Plugin Structure

Valgrind Plugin Source Code Structure:

.
└── MYPLUGIN
    ├── docs
    │   └── ...
    ├── tests
    │   └── ...
    ├── Makefile.am
    ├── PLUGIN_main.c
    └── (maybe) other files

最上層的 folder 是 plugin 的名稱 (可能有 exp- 作為 prefix 表示 experimental), 接著 folder 裡會有 PLUGIN_main.c, 裡面主要大概都會有以下 function (當然有另外的):

  • PLUGIN_pre_clo_init
    • regist by VG_DETERMINE_INTERFACE_VERSION

  • PLUGIN_post_clo_init
    • regist by VG_(basic_tool_funcs) in PLUGIN_pre_clo_init

  • PLUGIN_instrument
    • regist by VG_(basic_tool_funcs) in PLUGIN_pre_clo_init

  • PLUGIN_fini
    • regist by VG_(basic_tool_funcs) in PLUGIN_pre_clo_init

  • PLUGIN_print_usage
    • regist by VG_(needs_command_line_options) in PLUGIN_pre_clo_init

  • PLUGIN_print_debug_usage
    • regist by VG_(needs_command_line_options) in PLUGIN_pre_clo_init

  • PLUGIN_process_cmd_line_option
    • regist by VG_(needs_command_line_options) in PLUGIN_pre_clo_init

「clo」 := 「command line options」

Valgrind for Unix-like command

$ echo "hello" > test.txt
$ valgrind --tool=exp-dhat cat test.txt
==18771== DHAT, a dynamic heap analysis tool
==18771== NOTE: This is an Experimental-Class Valgrind Tool
==18771== Copyright (C) 2010-2013, and GNU GPL'd, by Mozilla Inc
==18771== Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright info
==18771== Command: cat test.txt
==18771==
==18771==
==18771== ======== SUMMARY STATISTICS ========
==18771==
==18771== guest_insns:  173,876
==18771==
==18771== max_live:     138,829 in 30 blocks
==18771==
==18771== tot_alloc:    138,834 in 31 blocks
==18771==
==18771== insns per allocated byte: 1
==18771==
==18771==
==18771== ======== ORDERED BY decreasing "max-bytes-live": top 10 allocators ========
==18771==
==18771== -------------------- 1 of 10 --------------------
==18771== max-live:    135,167 in 1 blocks
==18771== tot-alloc:   135,167 in 1 blocks (avg size 135167.00)
==18771== deaths:      1, at avg age 2,840 (1.63% of prog lifetime)
==18771== acc-ratios:  0.00 rd, 0.00 wr  (6 b-read, 6 b-written)
==18771==    at 0x4C280B0: malloc (in /usr/lib/valgrind/vgpreload_exp-dhat-amd64-linux.so)
==18771==    by 0x405BE8: ??? (in /usr/bin/cat)
==18771==    by 0x402436: ??? (in /usr/bin/cat)
==18771==    by 0x4E4E78F: (below main) (in /usr/lib/libc-2.21.so)
==18771==
...
==18771==
==18771== -------------------- 4 of 10 --------------------
==18771== max-live:    120 in 1 blocks
==18771== tot-alloc:   120 in 1 blocks (avg size 120.00)
==18771== deaths:      1, at avg age 41,012 (23.58% of prog lifetime)
==18771== acc-ratios:  3.33 rd, 0.93 wr  (400 b-read, 112 b-written)
==18771==    at 0x4C280B0: malloc (in /usr/lib/valgrind/vgpreload_exp-dhat-amd64-linux.so)
==18771==    by 0x4E59202: _nl_load_locale_from_archive (in /usr/lib/libc-2.21.so)
==18771==    by 0x4E5867A: _nl_find_locale (in /usr/lib/libc-2.21.so)
==18771==    by 0x4E57EEE: setlocale (in /usr/lib/libc-2.21.so)
==18771==    by 0x401AAB: ??? (in /usr/bin/cat)
==18771==    by 0x4E4E78F: (below main) (in /usr/lib/libc-2.21.so)
==18771==
==18771== Aggregated access counts by offset:
==18771==
==18771== [   0]  2 2 2 2 2 2 2 2 26 26 26 26 26 26 26 26
==18771== [  16]  3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
==18771== [  32]  3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
==18771== [  48]  3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
==18771== [  64]  0 0 0 0 0 0 0 0 3 3 3 3 3 3 3 3
==18771== [  80]  3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
==18771== [  96]  3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
==18771== [ 112]  3 3 3 3 3 3 3 3
==18771==
...

Valgrind for Languages

Rust

把簡單的 Rust 程式 (空的 main) 丟下去跑, 發現竟然有 heap allocation (而且看起來有用到 pthread), 後來知道是 Rust std 的 startup 做的, 不過目前還不知道 std startup 會處理哪些事情 …

進入點在這檔案的 lang_start : src/libstd/rt/mod.rs

code:

// compiling with "rustc -C opt-level=3 -C prefer-dynamic -g empty.rs"
fn main () {
}

Valgrind:

$ valgrind --tool=exp-dhat ./empty
==12190== DHAT, a dynamic heap analysis tool
==12190== NOTE: This is an Experimental-Class Valgrind Tool
==12190== Copyright (C) 2010-2013, and GNU GPL'd, by Mozilla Inc
==12190== Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright info
==12190== Command: ./empty
==12190==
==12190==
==12190== ======== SUMMARY STATISTICS ========
==12190==
==12190== guest_insns:  1,002,143
==12190==
==12190== max_live:     792 in 2 blocks
==12190==
==12190== tot_alloc:    856 in 4 blocks
==12190==
==12190== insns per allocated byte: 1,170
==12190==
==12190==
==12190== ======== ORDERED BY decreasing "max-bytes-live": top 10 allocators ========
==12190==
==12190== -------------------- 1 of 10 --------------------
==12190== max-live:    552 in 1 blocks
==12190== tot-alloc:   552 in 1 blocks (avg size 552.00)
==12190== deaths:      1, at avg age 133,882 (13.35% of prog lifetime)
==12190== acc-ratios:  6.06 rd, 2.56 wr  (3,348 b-read, 1,414 b-written)
==12190==    at 0x4C280B0: malloc (in /usr/lib/valgrind/vgpreload_exp-dhat-amd64-linux.so)
==12190==    by 0x54A0B9C: __fopen_internal (in /usr/lib/libc-2.21.so)
==12190==    by 0x59E6F79: pthread_getattr_np (in /usr/lib/libpthread-2.21.so)
==12190==    by 0x4F1BC0E: rt::lang_start::hc2bc8270d37f18e3u3w (in /usr/lib/libstd-74fa456f.so)
==12190==    by 0x545878F: (below main) (in /usr/lib/libc-2.21.so)
==12190==
==12190== Aggregated access counts by offset:
==12190==
==12190== [   0]  227 223 223 223 0 0 0 0 215 215 215 215 215 215 215 215
==12190== [  16]  95 95 95 95 95 95 95 95 12 12 12 12 12 12 12 12
==12190== [  32]  17 17 17 17 17 17 17 17 12 12 12 12 12 12 12 12
==12190== [  48]  12 12 12 12 12 12 12 12 22 22 22 22 22 22 22 22
==12190== [  64]  9 9 9 9 9 9 9 9 10 10 10 10 10 10 10 10
==12190== [  80]  1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
==12190== [  96]  8 8 8 8 8 8 8 8 3 3 3 3 3 3 3 3
==12190== [ 112]  14 14 14 14 13 5 5 5 0 0 0 0 0 0 0 0
==12190== [ 128]  1 1 0 0 0 0 0 0 5 5 5 5 5 5 5 5
==12190== [ 144]  7 7 7 7 7 7 7 7 0 0 0 0 0 0 0 0
==12190== [ 160]  1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
==12190== [ 176]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==12190== [ 192]  9 9 9 9 0 0 0 0 0 0 0 0 0 0 0 0
==12190== [ 208]  0 0 0 0 0 0 0 0 15 15 15 15 15 15 15 15
==12190== [ 224]  5 5 5 5 7 7 7 7 4 4 4 4 4 4 4 4
==12190== [ 240]  1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
==12190== [ 256]  1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
==12190== [ 272]  1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
==12190== [ 288]  1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
==12190== [ 304]  1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
==12190== [ 320]  1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0
==12190== [ 336]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==12190== [ 352]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==12190== [ 368]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==12190== [ 384]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==12190== [ 400]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==12190== [ 416]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==12190== [ 432]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==12190== [ 448]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==12190== [ 464]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==12190== [ 480]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==12190== [ 496]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==12190== [ 512]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==12190== [ 528]  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
==12190== [ 544]  1 1 1 1 1 1 1 1
==12190==
==12190== -------------------- 2 of 10 --------------------
==12190== max-live:    240 in 1 blocks
==12190== tot-alloc:   240 in 1 blocks (avg size 240.00)
==12190== deaths:      1, at avg age 128,384 (12.81% of prog lifetime)
==12190== acc-ratios:  28.90 rd, 21.05 wr  (6,936 b-read, 5,053 b-written)
==12190==    at 0x4C280B0: malloc (in /usr/lib/valgrind/vgpreload_exp-dhat-amd64-linux.so)
==12190==    by 0x54A1837: getdelim (in /usr/lib/libc-2.21.so)
==12190==    by 0x59E701E: pthread_getattr_np (in /usr/lib/libpthread-2.21.so)
==12190==    by 0x4F1BC0E: rt::lang_start::hc2bc8270d37f18e3u3w (in /usr/lib/libstd-74fa456f.so)
==12190==    by 0x545878F: (below main) (in /usr/lib/libc-2.21.so)
==12190==
==12190== -------------------- 3 of 10 --------------------
==12190== max-live:    32 in 1 blocks
==12190== tot-alloc:   32 in 1 blocks (avg size 32.00)
==12190== deaths:      1, at avg age 4,949 (0.49% of prog lifetime)
==12190== acc-ratios:  0.00 rd, 1.50 wr  (0 b-read, 48 b-written)
==12190==    at 0x4C280B0: malloc (in /usr/lib/valgrind/vgpreload_exp-dhat-amd64-linux.so)
==12190==    by 0x4C2A45F: realloc (in /usr/lib/valgrind/vgpreload_exp-dhat-amd64-linux.so)
==12190==    by 0x59E6ED4: pthread_getattr_np (in /usr/lib/libpthread-2.21.so)
==12190==    by 0x4F1BC0E: rt::lang_start::hc2bc8270d37f18e3u3w (in /usr/lib/libstd-74fa456f.so)
==12190==    by 0x545878F: (below main) (in /usr/lib/libc-2.21.so)
==12190==
==12190== Aggregated access counts by offset:
==12190==
==12190== [   0]  1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
==12190== [  16]  2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
==12190==
==12190== -------------------- 4 of 10 --------------------
==12190== max-live:    32 in 1 blocks
==12190== tot-alloc:   32 in 1 blocks (avg size 32.00)
==12190== deaths:      1, at avg age 31,008 (3.09% of prog lifetime)
==12190== acc-ratios:  1.00 rd, 1.00 wr  (32 b-read, 32 b-written)
==12190==    at 0x4C2A1A0: calloc (in /usr/lib/valgrind/vgpreload_exp-dhat-amd64-linux.so)
==12190==    by 0x546E2F1: __cxa_thread_atexit_impl (in /usr/lib/libc-2.21.so)
==12190==    by 0x4F050AC: sys_common::thread_info::set::h411b7bc6f4e0436cEwr (in /usr/lib/libstd-74fa456f.so)
==12190==    by 0x4F1BF32: rt::lang_start::hc2bc8270d37f18e3u3w (in /usr/lib/libstd-74fa456f.so)
==12190==    by 0x545878F: (below main) (in /usr/lib/libc-2.21.so)
==12190==
==12190== Aggregated access counts by offset:
==12190==
==12190== [   0]  2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
==12190== [  16]  2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
==12190==
==12190==
==12190==
==12190== ==============================================================
==12190==
==12190== Some hints: (see --help for command line option details):
==12190==
==12190== * summary stats for whole program are at the top of this output
==12190==
==12190== * --show-top-n=  controls how many alloc points are shown.
==12190==                  You probably want to set it much higher than
==12190==                  the default value (10)
==12190==
==12190== * --sort-by=     specifies the sort key for output.
==12190==                  See --help for details.
==12190==
==12190== * Each allocation stack, by default 12 frames, counts as
==12190==   a separate alloc point.  This causes the data to be spread out
==12190==   over far too many alloc points.  I strongly suggest using
==12190==   --num-callers=4 or some such, to reduce the spreading.
==12190==

Python

code:

# hello.py

print("Hello")

Valgrind:

$ valgrind python hello.py
==17971== Memcheck, a memory error detector
==17971== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==17971== Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright info
==17971== Command: python hello.py
==17971==
==17971== Invalid read of size 4
==17971==    at 0x4EDE88B: _PyObject_Free (obmalloc.c:1346)
==17971==    by 0x4EE7C25: tupledealloc (tupleobject.c:249)
==17971==    by 0x4EAE73E: code_dealloc (codeobject.c:365)
==17971==    by 0x4F5FA21: PyImport_ImportFrozenModuleObject (import.c:1275)
==17971==    by 0x4F5FAF9: PyImport_ImportFrozenModule (import.c:1291)
==17971==    by 0x4F6CE4D: import_init.isra.8 (pythonrun.c:283)
==17971==    by 0x4F6DA2E: _Py_InitializeEx_Private (pythonrun.c:449)
==17971==    by 0x4F82103: Py_Main (main.c:654)
==17971==    by 0x108C05: main (in /usr/bin/python3.4)
==17971==  Address 0x6030020 is 336 bytes inside a block of size 1,285 free'd
==17971==    at 0x4C2B200: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==17971==    by 0x4EAE6BE: code_dealloc (codeobject.c:364)
==17971==    by 0x4F5FA21: PyImport_ImportFrozenModuleObject (import.c:1275)
==17971==    by 0x4F5FAF9: PyImport_ImportFrozenModule (import.c:1291)
==17971==    by 0x4F6CE4D: import_init.isra.8 (pythonrun.c:283)
==17971==    by 0x4F6DA2E: _Py_InitializeEx_Private (pythonrun.c:449)
==17971==    by 0x4F82103: Py_Main (main.c:654)
==17971==    by 0x108C05: main (in /usr/bin/python3.4)
...
==17971==
==17971==
==17971== HEAP SUMMARY:
==17971==     in use at exit: 434,136 bytes in 341 blocks
==17971==   total heap usage: 7,684 allocs, 7,343 frees, 3,394,810 bytes allocated
==17971==
==17971== LEAK SUMMARY:
==17971==    definitely lost: 0 bytes in 0 blocks
==17971==    indirectly lost: 0 bytes in 0 blocks
==17971==      possibly lost: 2,888 bytes in 5 blocks
==17971==    still reachable: 431,248 bytes in 336 blocks
==17971==         suppressed: 0 bytes in 0 blocks
==17971== Rerun with --leak-check=full to see details of leaked memory
==17971==
==17971== For counts of detected and suppressed errors, rerun with: -v
==17971== Use --track-origins=yes to see where uninitialised values come from
==17971== ERROR SUMMARY: 631 errors from 56 contexts (suppressed: 0 from 0)
$ valgrind --tool=exp-dhat python hello.py
==18016== DHAT, a dynamic heap analysis tool
==18016== NOTE: This is an Experimental-Class Valgrind Tool
==18016== Copyright (C) 2010-2013, and GNU GPL'd, by Mozilla Inc
==18016== Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright info
==18016== Command: python hello.py
==18016==
==18016==
==18016== ======== SUMMARY STATISTICS ========
==18016==
==18016== guest_insns:  55,485,582
==18016==
==18016== max_live:     1,165,986 in 3,409 blocks
==18016==
==18016== tot_alloc:    3,020,163 in 7,049 blocks
==18016==
==18016== insns per allocated byte: 18
==18016==
==18016==
==18016== ======== ORDERED BY decreasing "max-bytes-live": top 10 allocators ========
==18016==
==18016== -------------------- 1 of 10 --------------------
==18016== max-live:    196,640 in 1 blocks
==18016== tot-alloc:   196,640 in 1 blocks (avg size 196640.00)
==18016== deaths:      none (none of these blocks were freed)
==18016== acc-ratios:  1.23 rd, 1.27 wr  (242,840 b-read, 251,368 b-written)
==18016==    at 0x4C280B0: malloc (in /usr/lib/valgrind/vgpreload_exp-dhat-amd64-linux.so)
==18016==    by 0x4EC776A: new_keys_object (dictobject.c:342)
==18016==    by 0x4EC9394: dictresize (dictobject.c:928)
==18016==    by 0x4EC9881: insertdict (dictobject.c:831)
==18016==    by 0x4F18614: PyUnicode_InternInPlace (unicodeobject.c:15074)
==18016==    by 0x4F5B8A9: r_object (marshal.c:1097)
==18016==    by 0x4F5BCFC: r_object (marshal.c:1313)
==18016==    by 0x4F5B27E: r_object (marshal.c:1123)
==18016==    by 0x4F5BC38: r_object (marshal.c:1283)
==18016==    by 0x4F5B27E: r_object (marshal.c:1123)
==18016==    by 0x4F5BC38: r_object (marshal.c:1283)
==18016==    by 0x4F5C22D: read_object (marshal.c:1381)
...
==18016==
==18016== Aggregated access counts by offset:
==18016==
==18016== [   0]  1799 1799 1799 1799 1799 1799 1799 1799 561 561 561 561 561 561 561 561
==18016== [  16]  6082 6082 6082 6082 6082 6082 6082 6082 13139 13139 13139 13139 13139 13139 13139 13139
==18016== [  32]  7513 7513 7513 7513 7512 7512 7512 7512 1667 1667 1667 1667 1667 1667 1667 1667
==18016== [  48]  211 211 211 211 211 211 211 211 693 693 693 693 693 693 693 693
==18016== [  64]  1111 1111 1111 1111 1111 1111 1111 1111 1431 1431 1431 1431 1431 1431 1431 1431
==18016== [  80]  106 106 106 106 106 106 106 106 383 383 383 383 383 383 383 383
...

IgProf

Introduction

CERN (歐洲核子研究組織) 在跑 LHC (大型強子對撞機) 做研究時, 也會需要寫大量的軟體來做運算, 其中的 CMS (Compact Muon Solenoid) 是個粒子偵測器, 用來觀察在 LHC 裡高能量碰撞下所產生的粒子和現象, 而 CMSSW 則是 CMS 的軟體的簡稱。 CMSSW 中大約有五百萬行自己寫的程式碼 (包含 C++、Python、Fortran), 這當中一個重要的問題就是記憶體, 這樣大的程式會需要工具來幫忙找出記憶體相關的問題 (例如 memory leak), 在 2003 年認為等 Valgrind 完善不是一個好選擇 (Valgrind 當時為 1.9.x 版), 於是先花了一天寫了叫做 MemProfLib 的 prototype。

MemProfLib 大概做到了這些事:

  • Malloc Hooks
    • __malloc_hook 來監控 allocation/deallocation,程式結束時還沒 deallocation 的資源就就回報說可能是 leak

    • 用 LD_PRELOAD 把 code 塞進去

    • atexit 來 dump

  • Flat output
    • 輸出成 xml,並用 XSLT 做分析

  • Instant gratification
    • 在設計整套工具前,證實是可以 work 的

在這後來產生了 IgProf (The Ignominious Profiler), 設計走向是要做 performance 和 memory 的 profiling (包含 backtrace), 而且不需要 kernel 支援、不需要 superuser 的權限, 目標用戶當然是在 CMS 的人們, 並且要支援多個平台 (x86、x86_64、ARM32、ARM64)。

這時已經幾件事情要注意了:

  • 避免 platform specific API,
    • 例如 glibc 的 __malloc_hook

  • 彈性
    • 預期不只 hook malloc (還會有例如 read/write 需要 hook)

  • 安全性
    • 除了一般的 malloc 外,還需要 hook 可能會干擾 profiler 的 function (例如 fork)

    • 可能還需要關掉一些東西 (例如 explicit call to signal)

    • 最後可以放心的 hook 到 exit 和 _exit 來 dump 出 profile 結果

IgProf 的內部大概有這些東西:

  • Dynamic instrumentation (IgHook)

  • Memory (by hooking into malloc) and performance profiler (via SIGPROF / SIGALRM)

  • Full backtrace information (via libunwind)

  • Analyser tool (igprof-analyse)

  • Simple web frontend (igprof-navigator)

在找 backtrace 的時候, 原本是用 backtrace() , 但後來為了 reliability 而改用 libunwind 。 在使用過程中, 因為要跑的程式每秒都有大量的 allocations, 所以 memory profiling 會變得太慢 (因為很多 unwindings), 後來改進了 libunwind 裡的作法, 不做完整的 DWARF unwind, 只做簡單的 stack walk, 行不通時才 fallback 回去做完整的 unwind。 後來貢獻回 libunwind, 分別有 x86_64 (by Lassi Tuura) 和 ARM32/ARM64 (by Filip Nybäck) 的實作, 其中據說有人的程式 profiling 獲得了 30x 的加速 !?

使用

$ LD_PRELOAD=/tmp/lib/libigprof.so igprof -j -d -mp -z -o igprof.mp.gz ./hello
$ igprof-analyse --sqlite -d -v -g igprof.mp.gz | sqlite3 igprof.sqlite3
$ igprof-navigator igprof.sqlite3   # open web view

$ LD_PRELOAD=/tmp/lib/libigprof.so igtrace -tm bin/single-heap-vector
*** MALLOC 1048544 bytes => 0x7f270794a010, by bin/single-heap-vector [thread 139805608687424 pid 19071]
*** MALLOC 1048544 bytes => 0x7f2706094010, by bin/single-heap-vector [thread 139805608687424 pid 19071]
*** MALLOC 400 bytes => 0x11b1d20, by bin/single-heap-vector [thread 139805608687424 pid 19071]

$ LD_PRELOAD=/tmp/lib/libigprof.so igtrace -d  bin/single-heap-vector
*** IgProf(19149, 1436687497.170): tracing activated in bin/single-heap-vector
*** IgProf(19149, 1436687497.170): tracing options: throw
*** IgProf(19149, 1436687497.171): __cxa_throw (0x7ffaaeb49b90): instrumenting 6 bytes into 0x7ffaaf29d004
*** IgProf(19149, 1436687497.171): tracing exceptions thrown

$ LD_PRELOAD=/tmp/lib/libigprof.so igtrace -d -tm bin/single-heap-vector
*** IgProf(19136, 1436687479.637): tracing activated in bin/single-heap-vector
*** IgProf(19136, 1436687479.637): tracing options: mem
*** IgProf(19136, 1436687479.637): malloc (0x7fc0fa5d4850): instrumenting 6 bytes into 0x7fc0fb5f7004
*** IgProf(19136, 1436687479.637): malloc (0x7fc0fa5d4850): hook trampoline already installed, ignoring
*** IgProf(19136, 1436687479.638): tracing memory allocations
*** MALLOC 1048544 bytes => 0x7fc0fb6cc010, by bin/single-heap-vector [thread 140466829711168 pid 19136]
*** MALLOC 1048544 bytes => 0x7fc0f9e16010, by bin/single-heap-vector [thread 140466829711168 pid 19136]
*** MALLOC 400 bytes => 0xaefd20, by bin/single-heap-vector [thread 140466829711168 pid 19136

Running Valgrind on Android

  • Valgrind - README.android

  • Android NDK (Native Development Kit)
    • toolset 讓 programmer 可以用 native-code language (例如 C、C++) 來撰寫 Android 上的程式

下載 android-ndk-r10e-linux-x86_64.bin 和 Valgrind source code 來編

Valgrind SVN

Valgrind

r15403 (2015-07-08)

Android NDK

android-ndk-r10e-linux-x86_64.bin

Platform

Android 21 (ARM)

Target CPU

ARMv7

Toolchain

GCC 4.9 (ARM, Android EABI)

$ wget http://dl.google.com/android/ndk/android-ndk-r10e-linux-x86_64.bin
$ chmod u+x android-ndk-r10e-linux-x86_64.bin
$ ./android-ndk-r10e-linux-x86_64.bin
$ export NDKROOT=/path/to/android-ndk-r10e  # modify your path

# build Valgrind
$ svn co svn://svn.valgrind.org/valgrind/trunk valgrind
$ cd valgrind
$ export AR=$NDKROOT/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/arm-linux-androideabi-ar
$ export LD=$NDKROOT/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/arm-linux-androideabi-ld
$ export CC=$NDKROOT/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/arm-linux-androideabi-gcc
$ ./autogen.sh
$ CPPFLAGS="--sysroot=$NDKROOT/platforms/android-21/arch-arm" \
      CFLAGS="--sysroot=$NDKROOT/platforms/android-21/arch-arm" \
      ./configure --prefix=/data/local/Inst \
      --host=armv7-unknown-linux --target=armv7-unknown-linux \
      --with-tmpdir=/sdcard
$ make -j8
$ make -j8 install DESTDIR=`pwd`/Inst
$ file Inst/data/local/Inst/bin/valgrind    # Check
Inst/data/local/Inst/bin/valgrind: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), statically linked, not stripped

這邊編譯時有遇到 conflicting types for 'Elf32_Nhdr' 的問題, 後來去 coregrind/m_coredump/coredump-elf.c 裡面把那部份的 code 刪掉就可以了, 與此同時發現有人送過 bug report、patch , 不過看來現在還沒 merge 進 Valgrind SVN, 另外 AOSP 的 Valgrind 則是在 6 個禮拜前修了這個問題。

Valgrind SVN (round 2)

Valgrind

r15574 (2015-08-21)

Android NDK

android-ndk-r10e-linux-x86_64.bin

Platform

Android 21 (ARM)

Target CPU

ARMv7

Toolchain

GCC 4.9 (ARM, Android EABI)

AOSP Valgrind

AOSP 版的 Valgrind 有針對 Android 修正編譯問題以及其他的調整

Valgrind

721e6a4 (2015-06-16)

Android NDK

android-ndk-r10e-linux-x86_64.bin

Platform

Android 21 (ARM)

Target CPU

ARMv7

Toolchain

GCC 4.9 (ARM, Android EABI)

$ wget http://dl.google.com/android/ndk/android-ndk-r10e-linux-x86_64.bin
$ chmod u+x android-ndk-r10e-linux-x86_64.bin
$ ./android-ndk-r10e-linux-x86_64.bin
$ export NDKROOT=/path/to/android-ndk-r10e  # modify your path

# build Valgrind
$ git clone https://android.googlesource.com/platform/external/valgrind/
$ cd valgrind
$ export AR=$NDKROOT/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/arm-linux-androideabi-ar
$ export LD=$NDKROOT/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/arm-linux-androideabi-ld
$ export CC=$NDKROOT/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/arm-linux-androideabi-gcc
$ ./autogen.sh
$ CPPFLAGS="--sysroot=$NDKROOT/platforms/android-21/arch-arm" \
      CFLAGS="--sysroot=$NDKROOT/platforms/android-21/arch-arm" \
      ./configure --prefix=/data/local/Inst \
      --host=armv7-unknown-linux --target=armv7-unknown-linux \
      --with-tmpdir=/sdcard
$ make -j8
$ make -j8 install DESTDIR=`pwd`/Inst
$ file Inst/data/local/Inst/bin/valgrind    # Check
Inst/data/local/Inst/bin/valgrind: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), statically linked, not stripped

# push to device
$ adb push Inst /

Running Valgrind on Android

一個成功 cross-compile 的 Valgrind 可以像一般使用一樣, 直接用 $ valgrind COMMAND 就可以執行內部的指令, 但是對於 Android 上的其他應用程式 (例如 browser) 則需做額外的處理, 因為那些程式一般是用 Android 的 Activity Manager (am) 來開啟, 如果是在 Valgrind 後面接 Activity Manager 的話會在開啟程式後就離開, 無法對程式進行我們想要的 instrumentation, 解法是依然使用 Activity Manager 開啟程式, 但是把 Valgrind 設成該程式的 wrapper, 透過 Activity Manager 把 Valgrind 跑起來, 這樣就可以避開這個問題了。

(Notice: 如果是在 Android Emulator 上面跑的話,可能會需要 --kernel-variant=android-emulator-no-hw-tls)

script 1 : start_valgrind.sh

#!/system/bin/sh

PACKAGE="com.android.browser"

export TMPDIR=/data/data/$PACKAGE

VGPARAMS="--log-file=$TMPDIR/valgrind.log.%p --error-limit=no --trace-children=yes"

# Memcheck tool
VGPLUGIN="--tool=memcheck --leak-check=full --show-reachable=yes"

echo "valgrind args: $*"
exec /data/local/Inst/bin/valgrind $VGPARAMS $VGPLUGIN $*

stcript 2 : bootstrap_valgrind.sh

#!/usr/bin/env sh

PACKAGE="com.android.browser"
ACTIVITY=".BrowserActivity"


adb push start_valgrind.sh /data/local/Inst/bin/
adb shell chmod 777 /data/local/Inst/bin/start_valgrind.sh

adb root
adb shell setprop wrap.$PACKAGE "logwrapper /data/local/Inst/bin/start_valgrind.sh"

echo "wrap.$PACKAGE: $(adb shell getprop wrap.$PACKAGE)"

# -S: force stop the target app before starting the activity
# -D: enable debugging
# -a: <ACTION> Specify the intent action, such as "android.intent.action.VIEW". You can declare this only once.
# -n: <COMPONENT> Specify the component name with package name prefix to create an explicit intent, such as "com.example.app/.ExampleActivity".

adb shell am start -S -a android.intent.action.MAIN -n $PACKAGE/$ACTIVITY

adb logcat -c   # -c: clears (flushes) the entire log and exits.
adb logcat

Problems

Unhandled Instruction

disInstr(arm): unhandled instruction: 0xEC510F1E
                cond=14(0xE) 27:20=197(0xC5) 4:4=1 3:0=14(0xE)
==1897== valgrind: Unrecognised instruction at address 0x4b27948.
==1897==    at 0x4B27948: _armv7_tick (in /system/lib/libcrypto.so)

Contribute to AOSP Valgrind

  • Android Code Review
    • 註冊帳號的方法就是直接用 Google 帳號登入

    • 註冊完去 setting 裡點 Contributor Agreement

Questions

對已經在執行的程式掛上 Valgrind ?

不可行,Valgrind 內在執行程式的環境跟一般情況差很多 (例如 memory layout 不同), 所以 Valgrind 需要在一開始就取得所有的掌控權。

Kernel Memory Leak Detect ?

Valgrind for Kernel ?

Valgrind instrument 的對象是 user-space 的程式, kernel 的話不太行,不知道要跟 QEMU 搭配使用來 instrument kernel 需要多大的修改?