Bug 591504

+++ This bug was initially created as a clone of Bug #588945 +++

Description of problem:
When the core file is large and sparse abrtd slows down the system up to 240x.
GDB gdb.base/bigcore.exp explicitly exploits this problem but it can be seen in other real world core dumps.
If nothing else abrtd should at least optimize write(usercorefile,zeroes) to lseek().

Version-Release number of selected component (if applicable):
abrt-1.0.9-2.fc12.x86_64

How reproducible:
Always.

Steps to Reproduce:
Download some gdb.
./configure
make
cd gdb/testsuite
make site.exp
time runtest gdb.base/bigcore.exp
service abrtd stop
time runtest gdb.base/bigcore.exp

Actual results:
real	1m41.021s (Keith Seitz has reported ~8min on his box)
real	0m2.223s

Expected results:
real	<few secs>
real	0m2.223s

Additional info:
read(1, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 4096) = 4096
write(3, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 4096) = 4096
...
  PID TTY      STAT   TIME COMMAND
   12 ?        S      0:01  \_ [khelper]
21699 ?        D      0:02  |   \_ /usr/libexec/abrt-hook-ccpp /var/cache/abrt 21696 6 502 17179869184
...
/proc/21699/fd/
lr-x------ 1 root root 64 2010-05-04 23:31 0 -> pipe:[11399566]
lrwx------ 1 root root 64 2010-05-04 23:31 1 -> /var/cache/abrt/ccpp-1273008577-21696/coredump\ (deleted)
lrwx------ 1 root root 64 2010-05-04 23:31 2 -> socket:[11401038]
l-wx------ 1 root root 64 2010-05-04 23:31 3 -> /home/.../gdb/testsuite/core.21696

--- Additional comment from jan.kratochvil on 2010-05-04 17:55:56 EDT ---

Maybe some hardlink would also help etc., unaware what abrt does there.

--- Additional comment from dvlasenk on 2010-05-07 08:47:03 EDT ---

Created an attachment (id=412336)
Proposed fix

Run tested.

--- Additional comment from dvlasenk on 2010-05-07 09:15:20 EDT ---

"time runtest gdb.base/bigcore.exp" with this patch went down from 

real	9m23.708s
user	0m0.285s
sys	0m22.819s

to

real	0m35.821s
user	0m0.318s
sys	0m8.738s