At Tue, 28 Sep 2004 12:15:58 +0200, Christoph Hellwig wrote: > > Recent versions of SuSE (e.g. SuSE 9.1, SLES 9) and Red Hat (RHEL 3AS, > > Fedora Core >= 1) distributions provide a support library with glibc to > > allow users to make use of the kernel's asynchronous IO interfaces. > > This additional library offers a higher performing alternative to the > > existing user-space only asynchronous IO support provided by librt. The > > kernel AIO support is made available via the 'librtkaio.so' shared > > library, which is packaged an addon in the SuSE and Red Hat source RPMs > > for glibc. > > Note that we only support AIO for direct (unbuffered) I/O to regular > files or block devices, but not AIO for networking or the normal > buffered file I/O. Thus I don't think this is worthwile, the few users > for the specific subset we have (databases mostly) tend to be written to > use RedHat or oracles libaio.
Agreed. In the latest -mm tree, patches from AIO project are included that can do buffered I/O, but that does not still have aio fsync. It's sure 2.6.9-rc does not have such patches. I guess RedHat and SuSE guys applied it for database applications. Ulrich Drepper said the current librt's AIO has good POSIX conformance. I asked about this issue to libc-alpha, Ulrich just said the kernel support is still insufficient. It fascinates me there are some area to work in the kernel side aio support. I think debian gets the limited advantage to use rtkaio instead of the current librt. I guess once kernel side is completely ready, librtkaio replaces the current userland librt implementation. Regards, -- gotom -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
