Hello, Eric W. Biederman wrote: >> One visible difference is lack of timestamp update. Is there any use >> case where sysfs file mode changing needs to be fast?\ > > Not really. If the time changes we set something besides ATTR_MODE > like ATTR_MTIME or ATTR_CTIME. If we come in through any of the > user space entry points ATTR_CTIME appears to be set so this optimization > will not trigger. > > I think there are cases where we only opportunistically track time > changes, when the structure is allocated that this changes but it > is a very small percentage of the time. > > The practical effect of my changes should be that we only track timestamps > when user space actually performs an explicit change to the file. > > If someone was depending on some weird indirect side effect like that > on one of the 5-6 files that calls sysfs_chmod let's make it explicit. > > For me this isn't about making this go faster. This is about keeping > the sysfs data structures small when we can. > > It doesn't really complicate the code and we wind up doing the obvious thing. Well, it doesn't add a lot of complexity but also seems pointless when there basically is no use case which would benefit from this change. I suppose it's upto the maintainer. Greg? Thanks. -- tejun -- 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
