From: arjen at react dot com
Operating system: Linux
PHP version: 7.0.0RC8
Package: Scripting Engine problem
Bug Type: Bug
Bug description:Script extreme slow compared to 5.6, MAP_HUGETLB problem?
Description:
------------
Testcase runs in 6.7 sec.
1.7 sec in PHP 5.6.
strace reports lots of ENOMEM (Cannot allocate memory) warnings:
munmap(0x7fd131400000, 2097152) = 0
mmap(NULL, 2097152, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB, -1, 0) = -1 ENOMEM (Cannot
allocate memory)
mmap(NULL, 2097152, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7fd131400000
madvise(0x7fd131400000, 2097152, MADV_HUGEPAGE) = 0
munmap(0x7fd131400000, 2097152) = 0
mmap(NULL, 2097152, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB, -1, 0) = -1 ENOMEM (Cannot
allocate memory)
mmap(NULL, 2097152, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0x7fd131400000
madvise(0x7fd131400000, 2097152, MADV_HUGEPAGE) = 0
[....]
Ultimately the memory allocation succeeds. With bigger javascript inputs
(it's a javascript minifier), running time can be in 10-60 minutes,
compared to 1-5 minutes under 5.6.
The PHP binary is compiled on a host with HUGETLB support, however the
target host (systemd-container) has not Hugepages (configured). 5.6
testing was done with same memory amount. There is enough (normal) free
memory.
cat /proc/meminfo
[..]
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Test script:
---------------
https://gist.github.com/arjenschol/49a847c07154b51130b2
Expected result:
----------------
Execution at least as fast as 5.6.
Actual result:
--------------
3-4x slower compared to 5.6.
--
Edit bug report at https://bugs.php.net/bug.php?id=70984&edit=1
--
Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=70984&r=trysnapshot54
Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=70984&r=trysnapshot55
Try a snapshot (trunk): https://bugs.php.net/fix.php?id=70984&r=trysnapshottrunk
Fixed in SVN: https://bugs.php.net/fix.php?id=70984&r=fixed
Fixed in release: https://bugs.php.net/fix.php?id=70984&r=alreadyfixed
Need backtrace: https://bugs.php.net/fix.php?id=70984&r=needtrace
Need Reproduce Script: https://bugs.php.net/fix.php?id=70984&r=needscript
Try newer version: https://bugs.php.net/fix.php?id=70984&r=oldversion
Not developer issue: https://bugs.php.net/fix.php?id=70984&r=support
Expected behavior: https://bugs.php.net/fix.php?id=70984&r=notwrong
Not enough info: https://bugs.php.net/fix.php?id=70984&r=notenoughinfo
Submitted twice: https://bugs.php.net/fix.php?id=70984&r=submittedtwice
register_globals: https://bugs.php.net/fix.php?id=70984&r=globals
PHP 4 support discontinued: https://bugs.php.net/fix.php?id=70984&r=php4
Daylight Savings: https://bugs.php.net/fix.php?id=70984&r=dst
IIS Stability: https://bugs.php.net/fix.php?id=70984&r=isapi
Install GNU Sed: https://bugs.php.net/fix.php?id=70984&r=gnused
Floating point limitations: https://bugs.php.net/fix.php?id=70984&r=float
No Zend Extensions: https://bugs.php.net/fix.php?id=70984&r=nozend
MySQL Configuration Error: https://bugs.php.net/fix.php?id=70984&r=mysqlcfg