Hi, Is there any way to find using kernel data structure, the VMA of a process belongs to stack or heap. It is easy to distinguish the VMA belongs to code segment or not from vm_area_struct structure, using "vm_flags" variable.
In "elf_core_dump()" function I'm planning to dump only code and data segments. Can any body please guide me... --Regards, rajesh On Wed, 05 Sep 2007 Dave Anderson wrote : >Rajesh wrote: >>Dave, >> >>Thanks for your explanation. >> >>Well the reason behind my questions is, we have an application running on >>customer site and the application consumes around 60GB of system memory. >>When this process receives the segmentation fault or signal abort, the kernel >>will start to take the process core dump. Here is the problem. Kernel takes >>at least 1hr (60-minutes) to come out from core dump. During this time the >>system is unresponsive (hung), and I feel it is because the system is >>entering into thrashing due to huge memory usage by the process. This long >>down time is not acceptable by the customer. >> >>So I started to find the better way or tackling the problem. >> >>1>First thing we thought is changing the system page size from 4KB to 8KB. >>Since this change could not be done on our x86_64 architecture, since x86_64 >>architecture doesnt support multi-page size option. >> >>2>We wrote a program using libbfd APIs and used with in our application. >>Whenever the SIGSEGV or SIGABRT is received by the process it will log the >>stack trace of all the threads within that process. This feature is not so >>effective or flexible as compared to process core dump. >> >>3>Last we thought of using kcore/vmcore to analyze the cause for SIGSEGV or >>SIGABRT. >> >>4>I have one more thought, making the elf_core_dump() function SMP. This >>function is responsible for dumping the core, and the function is present in >>/usr/src/linux/fs/binfmt_elf.c >> >> >>Any comments/ideas are welcome. >> >>--Regards, >>rajesh > >Maybe tinker with maydump()? > >If you know that the core dump contains the VMA's that are >not necessary to dump, such as large shared memory segments, >and you can identify them from the VMA, you can prevent >them from being copied to the core dump. There's this >patch floating around, which may have been updated: > > http://lkml.org/lkml/2007/2/16/149 > >Dave > > > >
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