On Sunday 23 of September 2012 18:10:30 Linus Torvalds wrote: > On Sat, Sep 22, 2012 at 11:09 PM, Paweł Sikora <pluto@xxxxxxxxxxxxx> wrote: > > > > br_read_lock(vfsmount_lock); > > The vfsmount_lock is a "local-global" lock, where a read-lock is > rather cheap and takes just a per-cpu lock, but the downside is that a > write-lock is *very* expensive, and can cause serious trouble. > > And the write lock is taken by the [un]mount() paths. Do *not* do > crazy things. If you do some insane "unmount and remount autofs" on a > 1s granularity, you're doing insane things. > > Why do you have that 1s timeout? Insane. 1s unmount timeout is *only* for fast bug reproduction (in few seconds after opteron startup) and testing potential patches. normally with 60s timeout it happens in few minutes..hours (depends on machine i/o+cpu load) and makes server unusable (permament soft-lockup). can we redesign vserver's mnt_is_reachable() for better locking to avoid total soft-lockup? BR, Paweł. ps). i'm adding Herbert to CC. -- 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
