Re: [RFC PATCH 1/5] mm, slab/slub: introduce kmalloc-reclaimable caches
From: Christopher Lameter <hidden>
Date: 2018-05-25 15:52:09
Also in:
linux-mm, lkml
On Thu, 24 May 2018, Vlastimil Babka wrote:
quoted hunk ↗ jump to hunk
diff --git a/include/linux/slab.h b/include/linux/slab.h index 9ebe659bd4a5..5bff0571b360 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h@@ -296,11 +296,16 @@ static inline void __check_heap_object(const void *ptr, unsigned long n, (KMALLOC_MIN_SIZE) : 16) #ifndef CONFIG_SLOB -extern struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1]; +extern struct kmem_cache *kmalloc_caches[2][KMALLOC_SHIFT_HIGH + 1]; #ifdef CONFIG_ZONE_DMA extern struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1]; #endif
In the existing code we used a different array name for the DMA caches. This is a similar situation. I would suggest to use kmalloc_reclaimable_caches[] or make it consistent by folding the DMA caches into the array too (but then note the issues below).
quoted hunk ↗ jump to hunk
@@ -536,12 +541,13 @@ static __always_inline void *kmalloc(size_t size, gfp_t flags) #ifndef CONFIG_SLOB if (!(flags & GFP_DMA)) { unsigned int index = kmalloc_index(size); + unsigned int recl = kmalloc_reclaimable(flags);
This is a hotpath reserved for regular allocations. The reclaimable slabs need to be handled like the DMA slabs. So check for GFP_DMA plus the reclaimable flags.
quoted hunk ↗ jump to hunk
@@ -588,12 +594,13 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node) if (__builtin_constant_p(size) && size <= KMALLOC_MAX_CACHE_SIZE && !(flags & GFP_DMA)) { unsigned int i = kmalloc_index(size); + unsigned int recl = kmalloc_reclaimable(flags);
Same situation here and additional times below.