On Thu, 2009-01-22 at 21:31 -0800, Andrew Morton wrote: > > On Thu, 22 Jan 2009 22:15:00 -0700 Jonathan Corbet <corbet@xxxxxxx> wrote: > > On Thu, 22 Jan 2009 06:51:04 -0800 > > Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > > OK, replacing a lock_kernel() with a spin_lock(&global_lock) is pretty > > > straightforwad. But it's really really sad. It basically leaves a > > > great big FIXME in there. It'd be better to fix it. > > > > > > We don't have a handy lock in struct file which could be borrowed. > > > > Yeah, I noticed that too. > > > > > - We could add one > > > > The problem there is that this bloats struct file, and that seemed like > > something worth avoiding. > > Not a big deal, really. There's one of these for each presently-open file. > It's not like dentries and inodes, which we cache after userspace has > closed off the file handles. I have to agree with Christoph. The priority here is breaking down the BKL and document all the things being protected by it and we've got a reasonably obvious patch in that direction. Meanwhile, there's not currently a pressing demand to make fasync in particular scale that I'm aware of. Having a single big lock here is quite possibly something we'll want to fix down the road, agreed, but until we can actually measure it hurting us, debating about whether to use a bit lock or reuse an existing lock or add a new lock to all struct files is a bit premature. -- http://selenic.com : development and support for Mercurial and Linux -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
