[RESEND v4 0/7] mm, slab: Make kmalloc_info[] contain all types of names

From: Pengfei Li
Date: Sun Sep 15 2019 - 13:08:27 EST


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

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_1-3 42188


bloat-o-meter
--
$ ./scripts/bloat-o-meter vmlinux.5.3-rc8 vmlinux.5.3-rc8+patch_1-7
add/remove: 1/2 grow/shrink: 6/65 up/down: 872/-1621 (-749)
Function old new delta
all_kmalloc_info - 832 +832
crypto_create_tfm 211 225 +14
ieee80211_key_alloc 1159 1169 +10
nl80211_parse_sched_scan 2787 2795 +8
tg3_self_test 4255 4259 +4
find_get_context.isra 634 637 +3
sd_probe 947 948 +1
nf_queue 671 670 -1
trace_parser_get_init 71 69 -2
pkcs7_verify.cold 318 316 -2
units 323 320 -3
nl80211_set_reg 642 639 -3
pkcs7_verify 1503 1495 -8
i915_sw_fence_await_dma_fence 445 437 -8
nla_strdup 143 134 -9
kmalloc_slab 102 93 -9
xhci_alloc_tt_info 349 338 -11
xhci_segment_alloc 303 289 -14
xhci_alloc_container_ctx 221 207 -14
xfrm_policy_alloc 277 263 -14
selinux_sk_alloc_security 119 105 -14
sdev_evt_send_simple 124 110 -14
sdev_evt_alloc 85 71 -14
sbitmap_queue_init_node 424 410 -14
regulatory_hint_found_beacon 400 386 -14
nf_ct_tmpl_alloc 91 77 -14
gss_create_cred 146 132 -14
drm_flip_work_allocate_task 76 62 -14
cfg80211_stop_iface 266 252 -14
cfg80211_sinfo_alloc_tid_stats 83 69 -14
cfg80211_port_authorized 218 204 -14
cfg80211_ibss_joined 341 327 -14
call_usermodehelper_setup 155 141 -14
bpf_prog_alloc_no_stats 188 174 -14
blk_alloc_flush_queue 197 183 -14
bdi_alloc_node 201 187 -14
_netlbl_catmap_getnode 253 239 -14
__igmp_group_dropped 629 615 -14
____ip_mc_inc_group 481 467 -14
xhci_alloc_command 221 205 -16
audit_log_d_path 204 188 -16
xprt_switch_alloc 145 128 -17
xhci_ring_alloc 378 361 -17
xhci_mem_init 3673 3656 -17
xhci_alloc_virt_device 505 488 -17
xhci_alloc_stream_info 727 710 -17
tcp_sendmsg_locked 3129 3112 -17
tcp_md5_do_add 783 766 -17
tcp_fastopen_defer_connect 279 262 -17
sr_read_tochdr.isra 260 243 -17
sr_read_tocentry.isra 337 320 -17
sr_is_xa 385 368 -17
sr_get_mcn 269 252 -17
scsi_probe_and_add_lun 2947 2930 -17
ring_buffer_read_prepare 103 86 -17
request_firmware_nowait 405 388 -17
ohci_urb_enqueue 3185 3168 -17
nfs_alloc_seqid 96 79 -17
nfs4_get_state_owner 1049 1032 -17
nfs4_do_close 587 570 -17
mempool_create_node 173 156 -17
ip6_setup_cork 1030 1013 -17
ida_alloc_range 951 934 -17
gss_import_sec_context 187 170 -17
dma_pool_alloc 419 402 -17
devres_open_group 223 206 -17
cfg80211_parse_mbssid_data 2406 2389 -17
ip_setup_cork 374 354 -20
kmalloc_caches 336 312 -24
__i915_sw_fence_await_sw_fence 429 405 -24
kmalloc_cache_name 57 - -57
new_kmalloc_cache 112 - -112
create_kmalloc_caches 270 148 -122
kmalloc_info 432 8 -424
Total: Before=14874616, After=14873867, chg -0.01%

Pengfei Li (7):
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
mm, slab: Return ZERO_SIZE_ALLOC for zero sized kmalloc requests
mm, slab_common: Make kmalloc_caches[] start at size KMALLOC_MIN_SIZE
mm, slab_common: Initialize the same size of kmalloc_caches[]
mm, slab_common: Modify kmalloc_caches[type][idx] to
kmalloc_caches[idx][type]

include/linux/slab.h | 136 ++++++++++++++------------
mm/slab.c | 11 ++-
mm/slab.h | 10 +-
mm/slab_common.c | 224 ++++++++++++++++++-------------------------
mm/slub.c | 12 +--
5 files changed, 183 insertions(+), 210 deletions(-)

--
2.21.0