On Mon, Sep 16, 2019 at 5:38 AM David Rientjes <rient...@google.com> wrote:
Thanks for your review comments! > > On Mon, 16 Sep 2019, Pengfei Li wrote: > > > diff --git a/mm/slab_common.c b/mm/slab_common.c > > index 2aed30deb071..e7903bd28b1f 100644 > > --- a/mm/slab_common.c > > +++ b/mm/slab_common.c > > @@ -1165,12 +1165,9 @@ void __init setup_kmalloc_cache_index_table(void) > > size_index[size_index_elem(i)] = 0; > > } > > > > -static void __init > > +static __always_inline void __init > > new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t > > flags) > > { > > - if (type == KMALLOC_RECLAIM) > > - flags |= SLAB_RECLAIM_ACCOUNT; > > - > > kmalloc_caches[type][idx] = create_kmalloc_cache( > > kmalloc_info[idx].name[type], > > kmalloc_info[idx].size, flags, 0, > > @@ -1185,30 +1182,22 @@ new_kmalloc_cache(int idx, enum kmalloc_cache_type > > type, slab_flags_t flags) > > void __init create_kmalloc_caches(slab_flags_t flags) > > { > > int i; > > - enum kmalloc_cache_type type; > > > > - for (type = KMALLOC_NORMAL; type <= KMALLOC_RECLAIM; type++) { > > - for (i = 0; i < KMALLOC_CACHE_NUM; i++) { > > - if (!kmalloc_caches[type][i]) > > - new_kmalloc_cache(i, type, flags); > > - } > > - } > > + for (i = 0; i < KMALLOC_CACHE_NUM; i++) { > > + if (!kmalloc_caches[KMALLOC_NORMAL][i]) > > + new_kmalloc_cache(i, KMALLOC_NORMAL, flags); > > > > - /* Kmalloc array is now usable */ > > - slab_state = UP; > > + new_kmalloc_cache(i, KMALLOC_RECLAIM, > > + flags | SLAB_RECLAIM_ACCOUNT); > > This seems less robust, no? Previously we verified that the cache doesn't > exist before creating a new cache over top of it (for NORMAL and RECLAIM). > Now we presume that the RECLAIM cache never exists. > Agree, this is really less robust. I have checked the code and found that there is no place to initialize kmalloc-rcl-xxx before create_kmalloc_caches(). So I assume that kmalloc-rcl-xxx is NULL. > Can we just move a check to new_kmalloc_cache() to see if > kmalloc_caches[type][idx] already exists and, if so, just return? This > should be more robust and simplify create_kmalloc_caches() slightly more. For better robustness, I will do it as you suggested in v5.