From: yuzhoujian <yuzhouj...@didichuxing.com>
I use perf to analyze the performance overhead for the server.
There are several dockers in the server. The php-fpm in the docker
will crash as long as the perf collects samples for all the cpus with call
graph option(perf record -ag). Below is the stack trace
in the coredump.
#0 0x00007f044ff447bd in re_compile_fastmap_iter (bufp=0x7f044ff447bd
<re_compile_fastmap_iter+1165>,
fastmap=0x46 <Address 0x46 out of bounds>,
init_state=<optimized out>, init_state=<optimized out>) at regcomp.c:407
407 if (__wcrtomb (buf, towlower (cset->mbchars[i]),
&state)
(gdb) bt
#0 0x00007f044ff447bd in re_compile_fastmap_iter (bufp=0x7f044ff447bd
<re_compile_fastmap_iter+1165>,
fastmap=0x46 <Address 0x46 out of bounds>, init_state=<optimized
out>, init_state=<optimized out>) at regcomp.c:407
#1 0x0000000000831160 in virtual_file_ex (state=0x7fff9c1a4f70,
path=<optimized out>, verify_path=0x0, use_realpath=1)
at /home/xiaoju/phpng/php-7.0.6/Zend/zend_virtual_cwd.c:1335
#2 0x00000000007aacee in expand_filepath_with_mode (
filepath=0x7f044d6020d8
"/home/xiaoju/ep/as/store//toggles/beatles_api_discovery_is_open_by_app",
real_path=0x7fff9c1a4fc0 "\360X\032\234\377\177",
relative_to=<optimized out>, relative_to_len=0, realpath_mode=1)
at
/home/xiaoju/phpng/php-7.0.6/main/fopen_wrappers.c:812
#3 0x00000000007c1536 in _php_stream_fopen (
filename=0x7f044d6020d8
"/home/xiaoju/ep/as/store//toggles/beatles_api_discovery_is_open_by_app",
mode=0xdbb1f1 "rb",
opened_path=0x0, options=0) at
/home/xiaoju/phpng/php-7.0.6/main/streams/plain_wrapper.c:970
#4 0x00000000007bd084 in _php_stream_open_wrapper_ex (
path=0x7f044d6020d8
"/home/xiaoju/ep/as/store//toggles/beatles_api_discovery_is_open_by_app",
mode=0xdbb1f1 "rb", options=8,
opened_path=0x0, context=0x7f044d65f4c0) at
/home/xiaoju/phpng/php-7.0.6/main/streams/streams.c:2060
#5 0x000000000071722b in zif_file_get_contents (execute_data=<optimized out>,
return_value=0x7f044d615540)
at
/home/xiaoju/phpng/php-7.0.6/ext/standard/file.c:544
#6 0x000000000065387c in phar_file_get_contents (execute_data=0x7f044d615570,
return_value=0x7f044d615540)
at
/home/xiaoju/phpng/php-7.0.6/ext/phar/func_interceptors.c:224))
I add some output info in the php source code, and found that virtual_file_ex
functions's rbp value is really strange,etc 0x1, 0x31. I guess when the perf
collects samples for all the cpus with -g option, it may destroy the php-fpm's
stack. When the perf is running without -g option, the php-fpm is normal. Who
have ever encountered similar problems?
BTW, OS in the server: Centos7.3 , Kernel version: 3.10.0-514.16.1.el7.x86_64.
php-fpm version: 7.0.6
Processor info: Intel(R) Xeon(R) CPU E5-2620 v3 @ 2.40GHz
