On Tue, Mar 15, 2011 at 9:44 PM, Randy Dunlap <rdunlap@xxxxxxxxxxxx> wrote: > On Tue, 15 Mar 2011 14:31:50 +0530 Aneesh Bhasin wrote: > >> Hi All, >> >> My apologies if this is not the right place for these type of >> questions - I do not know of a better place to ask this. >> >> I am trying to take out some memory figures from the /proc/<pid>/smaps >> interface (linux v2.6.35). However, I could not find what do the >> entries that have no name associated to them (no library path or >> binary path with these entries) mean. So, I wrote a test C program >> that allocates 100MB of memory (using malloc) and then writes to it in >> chunks of 10MB. I could see that the 'Size' and 'RSS' of one of the >> unnamed entries was increasing in accordance with the code, but there >> were several other such unnamed sections too - is there a way to know >> what and where do they come from. >> >> Also, I could see that for some process the smap interface was showing >> a '[heap]' entry but not for all - e.g. for my above test case, there >> was no '[heap]' entry, although I assumed the malloc should have >> reflected in the [heap]. Can someone please tell me (or point me in >> the right direction) why is heap entry there only for some processes ? >> >> Thanks in advance for any help.. > > Did you look at Documentation/filesystems/proc.txt ? > It has some info on smaps and maps. > > --- > ~Randy Thanks for the pointer Randy. I had a look at it and here is my understanding regarding this (please correct me if I am wrong) The entries in smaps (or maps) that have no name associated with them are anonymous memory regions. malloc, e.g. could allocate a memory using anonymous mmap for large blocks of memory due to efficiency reason. Are there any other such sources/reasons for creating anonymous memory regions ? I checked some of the above, by modifying my test program to allocate 1KB memory - this time it was attributed to [heap] whereas a memory allocation of 1MB was attributed to one of the anonymous memory regions. So, does that mean that all anonymous regions can be treated effectively as heap ? Also, is there a way in linux (without using dedicated tools like valgrind), to see how much heap or anonymous memory is attributed to code arising from a particular library/binary ? Thanks for the help ! Regards, Aneesh Bhasin -- To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs
