memory_get_peak_usage() is the maximum amount of memory used by the VM of PHP (but not by some extensions for instance) up until the point where that function is called. So the actual memory usage may be even higher IIRC. But yeah, you're basically right. I've explained in another message why it might be so much more than you expected (zval overhead, basically)
David On 07.06.2011, at 19:44, Mike van Riel wrote: > I have ran the script that you provided and got the following results: > > int(635192) > int(635944) > > Which is far less than the peak memory result. > > I use memory_get_peak_usage to measure what the worst case memory output > is in my application. I expect this to be the actual memory used (and > thus when the server starts swapping if this number exceeds the physical > memory). > > Is my assertion about the meaning of memory_get_peak_usage incorrect? > > Mike > > On Tue, 2011-06-07 at 16:28 +0200, David Zülke wrote: >> Please test the exact thing I suggested :) >> >> var_dump(memory_get_usage()); >> token_get_all(file_get_contents(<FILE>)); >> gc_collect_cycles(); >> var_dump(memory_get_usage()); >> >> memory_get_peak_usage() is irrelevant, and USE_ZEND_ALLOC won't give >> accurate results anymore when looking at memory usage. >> >> If the above gives the same numbers you got initially, then there's a >> memleak in token_get_all(). >> >> David >> >> >> On 06.06.2011, at 22:30, Mike van Riel wrote: >> >>> David and Pauli, >>> >>> When I change the test script to: >>> >>> var_dump(memory_get_peak_usage()); >>> gc_collect_cycles(); >>> token_get_all(file_get_contents(<FILE>)); >>> gc_collect_cycles(); >>> var_dump(memory_get_peak_usage()); >>> >>> And execute the following bash line preceding: >>> >>> export USE_ZEND_ALLOC=0 >>> >>> I get the following output: >>> >>> int(8240) >>> int(8240) >>> >>> When I remove the gc_collect_cycles I get the same result. >>> Even assigning the results to a variable do not increase the peak memory. >>> >>> FYI: When I change the argument of memory_get_peak_usage to 'true', I get >>> the following results: >>> >>> int(262144) >>> int(262144) >>> >>> This amount is astoundingly less than the previous conclusions and less >>> than my own calculations would show. >>> Of course this leads me to the following questions: >>> >>> 1. Does it hurt to disable the Zend MM? >>> 2. Can it be done from inside a PHP Script? >>> 3. Why is the memory consumption so much lower, even lower than my >>> calculations? >>> >>> I assume it is a good thing to at least try to create an easy way to >>> reproduce the issue (cannot include my test file) and create a bug report >>> about this :) >>> >>> Thank you for your assistance thus far. >>> >>> Mike >>> >>> On Sun, 5 Jun 2011 15:36:43 +0200, Julien Pauli wrote: >>>> Seems like leak. >>>> >>>> Try disabling ZendMM to see if something noticeable happens (memory >>>> peak should be lower). >>>> USE_ZEND_ALLOC=0 >>>> >>>> Cheers, >>>> Julien >>>> >>>> On Sun, Jun 5, 2011 at 2:01 PM, David Zülke >>>> <david.zue...@bitextender.com> wrote: >>>>> Smells like a memory leak if gc_collect_cycles() doesn't fix it. >>>>> >>>>> David >>> >>> >>> >>> -- >>> PHP Internals - PHP Runtime Development Mailing List >>> To unsubscribe, visit: http://www.php.net/unsub.php >>> >>> >> > > >
smime.p7s
Description: S/MIME cryptographic signature
