Messages in this thread | | | Date | Tue, 12 Feb 2008 03:37:10 +0900 | From | "KOSAKI Motohiro" <> | Subject | Re: [sample] mem_notify v6: usage example |
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Hi Andreas,
Thank you very good comment.
> Having such notification handled by glibc to free up unused malloc (or > any heap allocations) would be very useful, because even if a program > does "free" there is no guarantee the memory is returned to the kernel.
Yes, no guarantee. but current glibc-malloc very frequently return memory to kernel.
glibc default behavior
1. over 1M memory: return memory just free(3) called. (you can change threshold by MALLOC_MMAP_MAX_ environment) 2. more lower: return memory when exist continuous 128k at heap tail. (you can change threashold by MALLOC_TRIM_THRESHOLD_ environment)
if you know very memory consumption by already freed memory situation, please tell me situation detail and consumption memory size.
> I think that having a generic reservation framework is too complex, but > hiding the details of /dev/mem_notify from applications is desirable. > A simple wrapper (possibly part of glibc) to return the poll fd, or set > up the signal is enough.
Agreed. if large consumption situation exist, I'm behind you.
Thanks!
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