Red Hat Bugzilla – Bug 329141
Problem with write large buffer(>= 2Gb) under x86_64 kernel
Last modified: 2008-01-16 09:53:09 EST
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Description of problem:
I was told that we have made the decision there is 3 years to matche the
"upstream" behavior ( I think that means the 32-bits system behavoir).
If there is some improvement for supporting the real 64 bits IOs ?
Version-Release number of selected component (if applicable):
Steps to Reproduce:
In a C progam, write a buffer with his size >= 2Gb
I don't think this is a kernel problem.
And, you didn't report what actually happens.
Under any kernel version >= 2.6.11 (x86_64 system),
the C function write() or fwrite() failed to write
a buffer when his size >= 2Gb
For the older kernel versions 2.6.x (x<11), the tests
I'm reviewing this bug as part of the kernel bug triage project, an attempt to
isolate current bugs in the Fedora kernel.
I am CC'ing myself to this bug and will try and assist you in resolving it if I can.
There hasn't been much activity on this bug for a while. Could you tell me if
you are still having problems with the latest kernel?
If the problem no longer exists then please close this bug or I'll do so in a
few days if there is no additional information lodged.
I jsut installed the most recently debian kernel in the kernel archive
on my debian etch amd64 system (sorry I don't have no more Fedora x86_64
system). And I compile the following program
int main (int argc, char *argv)
size_to_wrt = 2147483648; /* can not beyond 2147483647 bytes */
buffer_to_wrt = malloc(size_to_wrt);
if(buffer_to_wrt == NULL) printf("Malloc error\n");
fd = open(argv, O_CREAT | O_RDWR, S_IRUSR|S_IWUSR);
size_wrten = write(fd, buffer_to_wrt, size_to_wrt);
if(size_wrten != size_to_wrt)
printf("Error message: %s\n", strerror(errno));
$cc -o test_write test_write.c
and run as
$ test_write foo
program run without error but the file written (foo) has not the good size,
which is 2147479552 byes, ie, 4096 bytes (just one page size) less than the
So we can not say this bug has been resolved yet.
We cannot debug issues exhibited on another distribution. For a case such as
this I would strongly recommend you file at the upstream kernel.org bugzilla,
where it will receive the attention of the mainline kernel team. Thank you for
taking the time to file the bug however I am closing this NOTABUG.
Whatever, I have just tested on a FC6 x86_64 system with kernel version
2.6.18-1.2798.fc6, there is exactely the identical behavior.
FC6 is no longer supported - you should test with a Fedora 8 system but again,
please do file this upstream if you believe it to be a kernel bug.
Ok, I'll report this to kernel bugzilla then. Sorry for the bothering.