Messages in this thread |  | | Date | Thu, 15 May 2003 21:19:21 +0200 | From | Andrea Arcangeli <> | Subject | Re: Race between vmtruncate and mapped areas? |
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On Thu, May 15, 2003 at 09:38:26AM -0700, Daniel McNeil wrote: > On Thu, 2003-05-15 at 02:40, Andrea Arcangeli wrote: > > On Thu, May 15, 2003 at 02:20:00AM -0700, Andrew Morton wrote: > > > Andrea Arcangeli <andrea@suse.de> wrote: > > > > > > > > and it's still racy > > > > > > damn, and it just booted ;) > > > > > > I'm just a little bit concerned over the ever-expanding inode. Do you > > > think the dual sequence numbers can be replaced by a single generation > > > counter? > > > > yes, I wrote it as a single counter first, but was unreadable and it had > > more branches, so I added the other sequence number to make it cleaner. > > I don't mind another 4 bytes, that cacheline should be hot anyways. > > You could use the seqlock.h sequence locking. It only uses 1 sequence > counter. The 2.5 isize patch 1 has a sequence lock without the spinlock > so it only uses 4 bytes and it is somewhat more readable. I don't > think it has more branches. > > I've attached the isize seqlock.h patch.
what do you think of the rmb vs mb in the reader side? Can I use rmb too? I used mb() to go safe. I mean gettimeofday is a no brainer since it does only reads inside the critical section anyways. But here I feel I need mb().
And yes, there are no more branches sorry, just an additional or.
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