On Thu, Aug 23, 2012 at 04:44:27PM +0400, Cyrill Gorcunov wrote: > On Thu, Aug 23, 2012 at 08:23:18AM -0400, J. Bruce Fields wrote: > > On Thu, Aug 23, 2012 at 02:43:23PM +0400, Cyrill Gorcunov wrote: > > > Hi guys, > > > > > > here is updated version of the fdinfo via procfs series, > > > the changes from previous one are the following > > > > > > - fhandle is carried inside inotify mark but this feature > > > is CONFIG dependent to not bloat the kernel for users > > > who don't need it > > > > As Al points out, this doesn't help much: if this feature is something a > > distro will want to provide, then in practice all their users are > > eventually going to end up with it turned on. > > > > Yes, I remember what Al has said, the problem is that this data attached > to inotify mark is not just a couple of bytes but rather about 136 bytes > per mark, and encoding this fhandle will take some cycles on mark creation > as well. Thus when in a sake of c/r we simply have no other way and are > to pay some trade off cost for c/r functionality, i don't think the > regular users (and note that CONFIG_CHECKPOINT_RESTORE is off by default) > should pay same cost for nothing. That's why I made it config dependant. > Again if you still think that making it config-option is a bad idea I'll > rip this symbols off, it's not a problem. Btw, Bruce, I forgot to mention that Linus and Andrew asked us to wrap all code related to c/r we bring in with CONFIG_CHECKPOINT_RESTORE symbol. So while wrapping show_fdinfo member in file_operations with CONFIG might be an overhead (as Al and Pavel pointed me) the fhandle in mark is reverse, a good candidate for CONFIG wrapping I think. Cyrill -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
