Re: [TUHS] V6 UNIX main() oddness

I don't see any reason why you can't make that optimization at that point. Nothing is going to come in and suddenly invalidate the inode between those two lines. I suspect it was an example of cut/paste-it is from some other part of the kernel. -----Original Message----- From: TUHS [mailto:tuhs-bounces@minnie.tuhs.org] On Behalf Of Noel Chiappa Sent: Thursday, January 25, 2018 1:43 PM To: tuhs(a)minnie.tuhs.org Cc: jnc(a)mercury.lcs.mit.edu Subject: [TUHS] V6 UNIX main() oddness So, while bringing up V6 on a hardware PDP-11/23 with an RK11 emulator using an SD card for storage which Dave Bridgham and I are doing, I found this piece of code in main() on V6 Unix: rootdir = iget(rootdev, ROOTINO); rootdir->i_flag =& ~ILOCK; u.u_cdir = iget(rootdev, ROOTINO); u.u_cdir->i_flag =& ~ILOCK; I don't get why two separate calls to iget(), with the same arguments; why not replace the second pair of lines with: u.u_cdir = rootdir; rootdir->i_count++; What am I missing? Noel