| Message ID | 20220409095305.586412-1-ohkwon1043@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/slab_common: move dma-kmalloc caches creation into new_kmalloc_cache() | expand |
On Sat, Apr 09, 2022 at 06:53:05PM +0900, Ohhoon Kwon wrote: > There are four types of kmalloc_caches: KMALLOC_NORMAL, KMALLOC_CGROUP, > KMALLOC_RECLAIM, and KMALLOC_DMA. While the first three types are > created using new_kmalloc_cache(), KMALLOC_DMA caches are created in a > separate logic. Let KMALLOC_DMA caches be also created using > new_kmalloc_cache(), to enhance readability. > > Historically, there were only KMALLOC_NORMAL caches and KMALLOC_DMA > caches in the first place, and they were initialized in two separate > logics. However, when KMALLOC_RECLAIM was introduced in v4.20 via > commit 1291523f2c1d ("mm, slab/slub: introduce kmalloc-reclaimable > caches") and KMALLOC_CGROUP was introduced in v5.14 via > commit 494c1dfe855e ("mm: memcg/slab: create a new set of kmalloc-cg-<n> > caches"), their creations were merged with KMALLOC_NORMAL's only. > KMALLOC_DMA creation logic should be merged with them, too. > > By merging KMALLOC_DMA initialization with other types, the following > two changes might occur: > 1. The order dma-kmalloc-<n> caches added in slab_cache list may be > sorted by size. i.e. the order they appear in /proc/slabinfo may change > as well. > 2. slab_state will be set to UP after KMALLOC_DMA is created. > In case of slub, freelist randomization is dependent on slab_state>=UP, > and therefore KMALLOC_DMA cache's freelist will not be randomized in > creation, but will be deferred to init_freelist_randomization(). > > Co-developed-by: JaeSang Yoo <jsyoo5b@gmail.com> > Signed-off-by: JaeSang Yoo <jsyoo5b@gmail.com> > Signed-off-by: Ohhoon Kwon <ohkwon1043@gmail.com> > --- > mm/slab_common.c | 20 +++++--------------- > 1 file changed, 5 insertions(+), 15 deletions(-) > > diff --git a/mm/slab_common.c b/mm/slab_common.c > index 6ee64d6208b3..eb95512de983 100644 > --- a/mm/slab_common.c > +++ b/mm/slab_common.c > @@ -849,6 +849,10 @@ new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags) > return; > } > flags |= SLAB_ACCOUNT; > +#ifdef CONFIG_ZONE_DMA > + } else if (type == KMALLOC_DMA) { > + flags |= SLAB_CACHE_DMA; > +#endif Maybe IS_ENABLED() would be better instead of ifdef for consistency? > } > > kmalloc_caches[type][idx] = create_kmalloc_cache( > @@ -877,7 +881,7 @@ void __init create_kmalloc_caches(slab_flags_t flags) > /* > * Including KMALLOC_CGROUP if CONFIG_MEMCG_KMEM defined > */ > - for (type = KMALLOC_NORMAL; type <= KMALLOC_RECLAIM; type++) { > + for (type = KMALLOC_NORMAL; type < NR_KMALLOC_TYPES; type++) { > for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) { > if (!kmalloc_caches[type][i]) > new_kmalloc_cache(i, type, flags); > @@ -898,20 +902,6 @@ void __init create_kmalloc_caches(slab_flags_t flags) > > /* Kmalloc array is now usable */ > slab_state = UP; > - > -#ifdef CONFIG_ZONE_DMA > - for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) { > - struct kmem_cache *s = kmalloc_caches[KMALLOC_NORMAL][i]; > - > - if (s) { > - kmalloc_caches[KMALLOC_DMA][i] = create_kmalloc_cache( > - kmalloc_info[i].name[KMALLOC_DMA], > - kmalloc_info[i].size, > - SLAB_CACHE_DMA | flags, 0, > - kmalloc_info[i].size); > - } > - } > -#endif > } > #endif /* !CONFIG_SLOB */ The patch overall looks good to me. Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Thanks! > -- > 2.25.1 > >
diff --git a/mm/slab_common.c b/mm/slab_common.c index 6ee64d6208b3..eb95512de983 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -849,6 +849,10 @@ new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags) return; } flags |= SLAB_ACCOUNT; +#ifdef CONFIG_ZONE_DMA + } else if (type == KMALLOC_DMA) { + flags |= SLAB_CACHE_DMA; +#endif } kmalloc_caches[type][idx] = create_kmalloc_cache( @@ -877,7 +881,7 @@ void __init create_kmalloc_caches(slab_flags_t flags) /* * Including KMALLOC_CGROUP if CONFIG_MEMCG_KMEM defined */ - for (type = KMALLOC_NORMAL; type <= KMALLOC_RECLAIM; type++) { + for (type = KMALLOC_NORMAL; type < NR_KMALLOC_TYPES; type++) { for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) { if (!kmalloc_caches[type][i]) new_kmalloc_cache(i, type, flags); @@ -898,20 +902,6 @@ void __init create_kmalloc_caches(slab_flags_t flags) /* Kmalloc array is now usable */ slab_state = UP; - -#ifdef CONFIG_ZONE_DMA - for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) { - struct kmem_cache *s = kmalloc_caches[KMALLOC_NORMAL][i]; - - if (s) { - kmalloc_caches[KMALLOC_DMA][i] = create_kmalloc_cache( - kmalloc_info[i].name[KMALLOC_DMA], - kmalloc_info[i].size, - SLAB_CACHE_DMA | flags, 0, - kmalloc_info[i].size); - } - } -#endif } #endif /* !CONFIG_SLOB */
There are four types of kmalloc_caches: KMALLOC_NORMAL, KMALLOC_CGROUP, KMALLOC_RECLAIM, and KMALLOC_DMA. While the first three types are created using new_kmalloc_cache(), KMALLOC_DMA caches are created in a separate logic. Let KMALLOC_DMA caches be also created using new_kmalloc_cache(), to enhance readability. Historically, there were only KMALLOC_NORMAL caches and KMALLOC_DMA caches in the first place, and they were initialized in two separate logics. However, when KMALLOC_RECLAIM was introduced in v4.20 via commit 1291523f2c1d ("mm, slab/slub: introduce kmalloc-reclaimable caches") and KMALLOC_CGROUP was introduced in v5.14 via commit 494c1dfe855e ("mm: memcg/slab: create a new set of kmalloc-cg-<n> caches"), their creations were merged with KMALLOC_NORMAL's only. KMALLOC_DMA creation logic should be merged with them, too. By merging KMALLOC_DMA initialization with other types, the following two changes might occur: 1. The order dma-kmalloc-<n> caches added in slab_cache list may be sorted by size. i.e. the order they appear in /proc/slabinfo may change as well. 2. slab_state will be set to UP after KMALLOC_DMA is created. In case of slub, freelist randomization is dependent on slab_state>=UP, and therefore KMALLOC_DMA cache's freelist will not be randomized in creation, but will be deferred to init_freelist_randomization(). Co-developed-by: JaeSang Yoo <jsyoo5b@gmail.com> Signed-off-by: JaeSang Yoo <jsyoo5b@gmail.com> Signed-off-by: Ohhoon Kwon <ohkwon1043@gmail.com> --- mm/slab_common.c | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-)