Re: Apache::Status Memory Usage metrics
On Thu, 28 Sep 2000, Doug MacEachern wrote: On Tue, 29 Aug 2000, Lyle D. Brooks wrote: This is my first time posting to this list, so forgive me if this question has been asked before (I did not see it in the archives or in the mod_perl guide). Apache::Status seems like a nice module, but I don't understand what the Memory usage section is telling me. For a given package, I have a function foo() that has a line like this. foo 48293 bytes | 1172 OPs Here's my questions... 1) 48293 bytes is what? Is that code?, stack?, data? or a combination of some of the three? TerseSize measures the sizeof() all structures (and strlen() of any strings) pointed to by the syntax (op) tree, lexical variables and globals. 2) 1172 OPs - what's an OPs? Is it good to have more or less? How does that affect memory usage? see matt's explanation. less is better. 3) Without changing the code, I can reload the memory usage page and the same function foo() will generally have the same number of bytes, but not always. The OPs always seem to remain the same number however. The bytes can vary but they don't seem to grow a great deal. Is this varying number a memory leak in the function? If not, what causes the number to vary from one invocation to the next? i'm not sure if stas has added a section to guide, but this has been explained a bunch of times here on the list. in a nutshell, Perl hangs It's there: http://perl.apache.org/guide/performance.html#Are_My_Variables_Shared_ And probably in a few other places, search for Apache::Peek and Devel::Peek. But these all talk about this effect on the way of showing something else. I guess I should make an explicit section that stresses this point. onto many of the allocations your scripts makes, such as the first time a variable is used by a script (they are all NULL at compile time), string copies, array and hash sizes, scratch pads for things like join, concatination, etc. B-LexInfo includes a handler to show this behavior in action. _ Stas Bekman JAm_pH -- Just Another mod_perl Hacker http://stason.org/ mod_perl Guide http://perl.apache.org/guide mailto:[EMAIL PROTECTED] http://apachetoday.com http://jazzvalley.com http://singlesheaven.com http://perlmonth.com perl.org apache.org
Re: Apache::Status Memory Usage metrics
On Tue, 29 Aug 2000, Lyle D. Brooks wrote: This is my first time posting to this list, so forgive me if this question has been asked before (I did not see it in the archives or in the mod_perl guide). Apache::Status seems like a nice module, but I don't understand what the Memory usage section is telling me. For a given package, I have a function foo() that has a line like this. foo 48293 bytes | 1172 OPs Here's my questions... 1) 48293 bytes is what? Is that code?, stack?, data? or a combination of some of the three? TerseSize measures the sizeof() all structures (and strlen() of any strings) pointed to by the syntax (op) tree, lexical variables and globals. 2) 1172 OPs - what's an OPs? Is it good to have more or less? How does that affect memory usage? see matt's explanation. less is better. 3) Without changing the code, I can reload the memory usage page and the same function foo() will generally have the same number of bytes, but not always. The OPs always seem to remain the same number however. The bytes can vary but they don't seem to grow a great deal. Is this varying number a memory leak in the function? If not, what causes the number to vary from one invocation to the next? i'm not sure if stas has added a section to guide, but this has been explained a bunch of times here on the list. in a nutshell, Perl hangs onto many of the allocations your scripts makes, such as the first time a variable is used by a script (they are all NULL at compile time), string copies, array and hash sizes, scratch pads for things like join, concatination, etc. B-LexInfo includes a handler to show this behavior in action.
Apache::Status Memory Usage metrics
This is my first time posting to this list, so forgive me if this question has been asked before (I did not see it in the archives or in the mod_perl guide). Apache::Status seems like a nice module, but I don't understand what the Memory usage section is telling me. For a given package, I have a function foo() that has a line like this. foo 48293 bytes | 1172 OPs Here's my questions... 1) 48293 bytes is what? Is that code?, stack?, data? or a combination of some of the three? 2) 1172 OPs - what's an OPs? Is it good to have more or less? How does that affect memory usage? 3) Without changing the code, I can reload the memory usage page and the same function foo() will generally have the same number of bytes, but not always. The OPs always seem to remain the same number however. The bytes can vary but they don't seem to grow a great deal. Is this varying number a memory leak in the function? If not, what causes the number to vary from one invocation to the next? More questions later... The documentation seemed to be silent in regards to answering these questions. Any insights would be much appreciated.
Re: Apache::Status Memory Usage metrics
On Tue, 29 Aug 2000, Lyle D. Brooks wrote: This is my first time posting to this list, so forgive me if this question has been asked before (I did not see it in the archives or in the mod_perl guide). Apache::Status seems like a nice module, but I don't understand what the Memory usage section is telling me. For a given package, I have a function foo() that has a line like this. foo 48293 bytes | 1172 OPs Here's my questions... 1) 48293 bytes is what? Is that code?, stack?, data? or a combination of some of the three? Code and data combined, AFAIK. Its data from some B::Terse or B::TerseSize module. See the documentation in that for more details. 2) 1172 OPs - what's an OPs? Is it good to have more or less? How does that affect memory usage? Perl code is based on OP codes, much like Java Bytecode. It is good to have less, as it means (sometimes) faster execution and less memory usage. -- Matt/ Fastnet Software Ltd. High Performance Web Specialists Providing mod_perl, XML, Sybase and Oracle solutions Email for training and consultancy availability. http://sergeant.org | AxKit: http://axkit.org
