On Wed, Jun 30, 2010 at 10:08:50PM +1000, Nick Piggin wrote: > On Wed, Jun 30, 2010 at 07:26:41PM +1000, Dave Chinner wrote: > > On Thu, Jun 24, 2010 at 01:02:56PM +1000, npiggin@xxxxxxx wrote: > > > Signed-off-by: Nick Piggin <npiggin@xxxxxxx> > > ..... > > > @@ -2194,6 +2198,58 @@ static inline void insert_inode_hash(str > > > > > > extern void file_sb_list_add(struct file *f, struct super_block *sb); > > > extern void file_sb_list_del(struct file *f); > > > +#ifdef CONFIG_SMP > > > + > > > +/* > > > + * These macros iterate all inodes on all CPUs for a given superblock. > > > + * rcu_read_lock must be held. > > > + */ > > > +#define do_inode_list_for_each_entry_rcu(__sb, __inode) \ > > > +{ \ > > > + int i; \ > > > + for_each_possible_cpu(i) { \ > > > + struct list_head *list; \ > > > + list = per_cpu_ptr((__sb)->s_inodes, i); \ > > > + list_for_each_entry_rcu((__inode), list, i_sb_list) > > > + > > > +#define while_inode_list_for_each_entry_rcu \ > > > + } \ > > > +} > > > + > > > +#define do_inode_list_for_each_entry_safe(__sb, __inode, __tmp) \ > > > +{ \ > > > + int i; \ > > > + for_each_possible_cpu(i) { \ > > > + struct list_head *list; \ > > > + list = per_cpu_ptr((__sb)->s_inodes, i); \ > > > + list_for_each_entry_safe((__inode), (__tmp), list, i_sb_list) > > > + > > > +#define while_inode_list_for_each_entry_safe \ > > > + } \ > > > +} > > > + > > > +#else > > > + > > > +#define do_inode_list_for_each_entry_rcu(__sb, __inode) \ > > > +{ \ > > > + struct list_head *list; \ > > > + list = &(sb)->s_inodes; \ > > > + list_for_each_entry_rcu((__inode), list, i_sb_list) > > > + > > > +#define while_inode_list_for_each_entry_rcu \ > > > +} > > > + > > > +#define do_inode_list_for_each_entry_safe(__sb, __inode, __tmp) \ > > > +{ \ > > > + struct list_head *list; \ > > > + list = &(sb)->s_inodes; \ > > > + list_for_each_entry_rcu((__inode), (__tmp), list, i_sb_list) > > > + > > > +#define while_inode_list_for_each_entry_safe \ > > > +} > > > > I can't say that I'm a great fan of hiding loop context in defines > > like this. It reminds far too much of how parts of Irix slowly > > ossified because they ended up mess of complex, fragile macros that > > nobody fully understood... > > It's not perfect. I think it is a lot better than open coding > (which I tried before) because that really muddies up the intention > of the loop body. Something like this doesn't seem particularly bad: static inline struct list_head * inode_get_sb_list(struct super_block *sb, int *i) { int cpu; cpu = cpumask_next(i, cpu_possible_mask); if (cpu >= nr_cpu_ids) return NULL; *i = cpu; #ifdef CONFIG_SMP return per_cpu_ptr(sb->s_inodes, cpu); #else return &sb->s_inodes; #endif } and: struct list_head *list; int i; .... i = -1; while ((list = inode_get_sb_list(sb, &i))) { list_for_each_entry_rcu(inode, tmp, list, i_sb_list) { ..... } } I'd much prefer this to hiding the outer loop in macros... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- 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