On Thu 26-03-09 01:17:06, Jiri Gaisler wrote: > Jan Kara wrote: > > Hi, > > > > thanks for the updated disassembly. > > > >> 55bab0: 82 10 60 01 or %g1, 1, %g1 > >> spin_unlock(&journal->j_list_lock); > >> 55bab4: 40 06 4b 20 call 6ee734 <_spin_unlock> > >> 55bab8: c2 24 e0 28 st %g1, [ %l3 + 0x28 ] > > OK, so it really seems that: > > jinode->i_flags |= JI_COMMIT_RUNNING; > > spin_unlock(&journal->j_list_lock); > > > > has been compiled to > > ld [ %l3 + 0x28 ], %g1 > > or %g1, 1, %g1 > > call 6ee734 <_spin_unlock> > > st %g1, [ %l3 + 0x28 ] > > > > Which seems like a bug in the compiler or in the way implement compiler > > barriers in spin_unlock() on UP sparc. Or is there some sparc magic by which > > this is correct code? Any clever sparc guy? > > > Looks fine to me - the store is made in the branch delay slot > of the call, so it will occur before the first instruction at > the call target address executes. Thanks for explanation. I knew sparc had some surprising features like this ;). Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
