On Thu, May 17, 2007 at 06:00:46AM +0100, Al Viro wrote: > On Thu, May 17, 2007 at 10:20:41AM +0530, Bharata B Rao wrote: > > From: Bharata B Rao <[EMAIL PROTECTED]> > > > > namespace_sem is a rwsem. It is acquired as read sem at only one place(used > > by /proc/mounts, /proc/<pid>/mounts and /proc/<pid>/mountstats). In all > > other > > cases it is acquired as a write sem. So, as there is not more than one > > reader > > for this sem, this can be a generic sem (and not rwsem) and if so it can be > > a mutex. > > Except that read accesses outnumber write ones by far and we have no reason > for serializing them against each other. NAK.
Ok, I wasn't aware that this rwsem had many concurrent readers. From whatever little I could see (during system boot and during kernel compilation with make -j), the number of concurrent readers very rarely touched 3 and was 1 mostly. May be there are other concurrent readers of this sem. Any idea from where they could be coming from ? Regards, Bharata. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
