On Mon, 2012-07-09 at 09:01 -0500, Christoph Lameter wrote: > > I was pointed by Glauber to the slab common code patches. I need some > > more time to read the patches. Now I think the slab/slot changes in this > > v3 are not needed, and can be ignored. > > That may take some kernel cycles. You have a current issue here that needs > to be fixed.
I'm a little confused ... and what need I do for the next step? > > > > down_write(&slub_lock); > > > - s = find_mergeable(size, align, flags, name, ctor); > > > + s = find_mergeable(size, align, flags, n, ctor); > > > if (s) { > > > s->refcount++; > > > /* > > > > ...... > > up_write(&slub_lock); > > return s; > > } > > > > Here, the function returns without name string n be kfreed. > > That is intentional since the string n is still referenced by the entry > that sysfs_slab_alias has created. I'm not sure whether the "referenced by ..." you mentioned is what I understood. From my understanding: if slab_state == SYS_FS, after return sysfs_create_link(&slab_kset->kobj, &s->kobj, name); is called, the name string passed in sysfs_slab_alias is no longer referenced (sysfs_new_dirent duplicates the string for sysfs to use). else, the name sting is referenced by al->name = name; temporarily. After slab_sysfs_init is finished, the name is not referenced any more. So in my patch (slub part), the string is duplicated here, and kfreed in slab_sysfs_init. > > But we couldn't kfree n here, because in sysfs_slab_alias(), if > > (slab_state < SYS_FS), the name need to be kept valid until > > slab_sysfs_init() is finished adding the entry into sysfs. > > Right that is why it is not freed and that is what fixes the issue you > see. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/