Trond Myklebust wrote:
On Wed, 2005-12-07 at 09:01 -0500, Peter Staubach wrote:
Kenny Simpson wrote:
Hi again,
I am seeing some odd behavior with O_DIRECT. If a file opened with O_DIRECT has a page mmap'd,
and the file is extended via pwrite, then the mmap'd region seems to get lost - i.e. it neither
takes up system memory, nor does it get written out.
I don't think that I understand why or how the kernel allows a file,
which was opened with O_DIRECT, to be mmap'd. The use of O_DIRECT
implies no caching and mmap implies the use of caching.
In this context it doesn't matter whether or not the you use the same
file descriptor. The problem is the same if my process opens the file
for O_DIRECT and then your process open it for normal I/O, and mmaps it.
Yup, same problem. Why is this allowed? Does it really work correctly?
Thanx...
ps
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
