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Re: jemalloc SEGV problem
mmap does not fail.
mamap does allocate memory for the variable "chunk"
and then when the program tries to modify "chunk" SEGV is recieved.
I checked the problem is below:
'pagesize_2pow' is calculated as
result = sysconf(_SC_PAGESIZE);
assert(result != -1);
pagesize = (unsigned) result;
* We assume that pagesize is a power of 2 when calculating
* pagesize_mask and pagesize_2pow.
assert(((result - 1) & result) == 0);
pagesize_mask = result - 1;
pagesize_2pow = ffs((int)result) - 1;
In my case case pagesize_2pow comes as 11.
Since sysconf(_SC_PAGESIZE) returns 4096.
If i retain the macro value CHUNK_2POW_DEFAULT as 20 and initialize
pagesize_2pow = 19
which means my pagesize is 2^20..
jemalloc() works fine , does not give any SEGV.
In anycase mamp () is not failing.
I feel the problem is with the alignment of the memory which is not happening
Also i checked none of the variables are overflowing.
Thanks & Regards,
2008/11/17 Christos Zoulas <christos%zoulas.com@localhost>:
> On Nov 17, 12:42pm, channa.kad%gmail.com@localhost (Channa) wrote:
> -- Subject: Re: jemalloc SEGV problem
> | Hi,
> | Ya i understand but when i changed the pagesize to 64K in mips arch
> | and retained the macro CHUNK_2POW_DEFAULT as present in jemalloc.c
> | original file.I dint get any seg fault.
> | But when i changed the pagesize again to 4K i got SEGV.
> | Regards,
> | Channa
> What does the ktrace of your program show? Does the mmap fail?
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