strace+ is an improved version of strace that collects stack traces associated with each system call. Since system calls require an expensive user-kernel context switch, they are often sources of performance bottlenecks. strace+ allows programmers to do more detailed system call profiling and determine, say, which call sites led to costly syscalls and thus have potential for optimization.

strace vs strace+

strace vs strace+

Build Pre-requisites

• binutils
• autoconf
• gdb
• make
• gcc-c++
• gcc
• gcc-x86_64-linux-gnu
• glibc-static
• python

Compile and Build strace+

1. Check out the source code from Git (requires git >= 1.6.6)

   $ git clone https://code.google.com/p/strace-plus/

2. Compile strace+

   $ cd strace-plus/
   $ autoreconf -f -i
   $ ./configure
   $ make
   $ cp strace strace+

Compile a "hello world" test program

1. Create a file named hello.c. hello.c is a simple program that makes four write system calls via printf statements:

   #include 
   
   void bar() {
     printf("bar\n");
     printf("bar again\n");
   }
   
   void foo() {
     printf("foo\n");
     bar();
   }
   
   int main() {
     printf("Hello world\n");
     foo();
     return 0;
   }

2. Compile it:

   $ gcc hello.c -o hello

3. Test:

   $ ./hello

4. Run strace+ on the hello executable to generate a trace file named hello.out.

   $ ./strace+ -o hello.out ./hello

5. Post-process hello.out to print out a list of system calls each augmented with stack traces

   python scripts/pretty_print_strace_out.py hello.out --trace

Build Statically

I like to always try and compile tools statically if possible. Especially in a case like this where you don't want strace+ to replace strace.

$ cd strace-plus/
$ export CFLAGS="-Os -fomit-frame-pointer -static -static-libgcc -ffunction-sections -fdata-sections -falign-functions=1 -falign-jumps=1 -falign-labels=1 -falign-loops=1 -fno-unwind-tables -fno-asynchronous-unwind-tables -Wl,--gc-sections -Wl,-Map=strace.mapfile"
$ autoreconf -i -f
$ ./configure
$ make CFLAGS="$CFLAGS"
$ cp strace strace+

# Normal strace
$ file /usr/bin/strace
/usr/bin/strace: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.18, stripped

# Static strace-plus
$ file strace+
strace+: ELF 64-bit LSB executable, x86-64, version 1 (GNU/Linux), statically linked, not stripped

Bash Aliases Functions

Useful to stick in your .bash_profile

Alias: enhanced strace

alias strace='command strace -fq -s1000  -e trace=all 2>&1'

Alias: trace file calls

alias stracef='command strace -fq -s1000  -e trace=file 2>&1'

Function: tputtrace

function tputtrace ()
{
  ( 2>&2 strace -s5000 -e write tput $1 2>&1 )  | tee -a /dev/stderr | grep --color=always -o '"[^"]*"';
}

See Also

vistrace: a visualization of strace