[PATCH v6 0/3] mm, slab: Make kmalloc_info[] contain all types of names

From: Pengfei Li
Date: Mon Sep 23 2019 - 08:27:47 EST


Changes in v6
--
1. abandon patch 4-7 (Because there is not enough reason to explain
that they are beneficial)

Changes in v5
--
1. patch 1/7:
- rename SET_KMALLOC_SIZE to INIT_KMALLOC_INFO
2. patch 5/7:
- fix build errors (Reported-by: kbuild test robot)
- make all_kmalloc_info[] static (Reported-by: kbuild test robot)
3. patch 6/7:
- for robustness, determine kmalloc_cache is !NULL in
new_kmalloc_cache()
4. add ack tag from David Rientjes

Changes in v4
--
1. [old] abandon patch 4/4
2. [new] patch 4/7:
- return ZERO_SIZE_ALLOC instead 0 for zero sized requests
3. [new] patch 5/7:
- reorder kmalloc_info[], kmalloc_caches[] (in order of size)
- hard to split, so slightly larger
4. [new] patch 6/7:
- initialize kmalloc_cache[] with the same size but different
types
5. [new] patch 7/7:
- modify kmalloc_caches[type][idx] to kmalloc_caches[idx][type]

Patch 4-7 are newly added, more information can be obtained from
commit messages.

Changes in v3
--
1. restore __initconst (patch 1/4)
2. rename patch 3/4
3. add more clarification for patch 4/4
4. add ack tag from Roman Gushchin

Changes in v2
--
1. remove __initconst (patch 1/5)
2. squash patch 2/5
3. add ack tag from Vlastimil Babka


There are three types of kmalloc, KMALLOC_NORMAL, KMALLOC_RECLAIM
and KMALLOC_DMA.

The name of KMALLOC_NORMAL is contained in kmalloc_info[].name,
but the names of KMALLOC_RECLAIM and KMALLOC_DMA are dynamically
generated by kmalloc_cache_name().

Patch1 predefines the names of all types of kmalloc to save
the time spent dynamically generating names.

These changes make sense, and the time spent by new_kmalloc_cache()
has been reduced by approximately 36.3%.

Time spent by new_kmalloc_cache()
(CPU cycles)
5.3-rc7 66264
5.3-rc7+patch 42188

Pengfei Li (3):
mm, slab: Make kmalloc_info[] contain all types of names
mm, slab: Remove unused kmalloc_size()
mm, slab_common: Use enum kmalloc_cache_type to iterate over kmalloc
caches

include/linux/slab.h | 20 -----------
mm/slab.c | 7 ++--
mm/slab.h | 2 +-
mm/slab_common.c | 99 ++++++++++++++++++++++++++++------------------------
4 files changed, 58 insertions(+), 70 deletions(-)

--
2.7.4