On Tue, 2005-03-01 at 11:33 +0100, Arjan van de Ven wrote: > On Tue, 2005-03-01 at 19:22 +0900, FUJITA Tomonori wrote: > > From: Arjan van de Ven <[EMAIL PROTECTED]> > > Subject: [Iscsitarget-devel] Re: [ANNOUNCE] iSCSI enterprise target software > > Date: Tue, 01 Mar 2005 10:46:03 +0100 > > > > > fsync or msync() ? I would imagine the target mmaping it's backend in > > > userspace and using msync() to kick off IO. At which point it's not that > > > much different from the control you do of the pagecache from inside the > > > kernel... > > > > Can we avoid calling mmap() and munmap() repeatedly with large disk? > > my server has 512Gb address space with 2.6.9/2.6.10, and a lot more than > that with the 2.6.11 kernel (4 level page tables rock). So the answer > would be yes. > > (and on old servers without 64 bit, you indeed need to mmap/munmap > lazily to create a window, but I suspect that the 3 Gb of address space > you have there can be managed smart to minimize the number of unmaps if > you really try)
note that on 32 bit servers the kernel side needs to do kmap() on the pages anyway, and that a kmap/kunmap series is very much equivalent to a mmap/munmap series in lots of ways, so I doubt that has many additional savings for doing it in kernel space. - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
