[PATCH v2 0/4] Update memcpy, memset etc. for M7/M8 architectures

From: Babu Moger
Date: Mon Aug 07 2017 - 19:53:26 EST

This series of patches updates the memcpy, memset, copy_to_user, copy_from_user
etc for SPARC M7/M8 architecture.

New algorithm here takes advantage of the M7/M8 block init store ASIs, with much
more optimized way to improve the performance. More detail are in code comments.

Tested and compared the latency measured in ticks(NG4memcpy vs new M7memcpy).

1. Memset numbers(Aligned memset)

No.of bytes NG4memset M7memset Delta ((B-A)/A)*100
(Avg.Ticks A) (Avg.Ticks B) (latency reduction)
3 77 25 -67.53
7 43 33 -23.25
32 72 68 -5.55
128 164 44 -73.17
256 335 68 -79.70
512 511 220 -56.94
1024 1552 627 -59.60
2048 3515 1322 -62.38
4096 6303 2472 -60.78
8192 13118 4867 -62.89
16384 26206 10371 -60.42
32768 52501 18569 -64.63
65536 100219 35899 -64.17


2. Memcpy numbers(Aligned memcpy)

No.of bytes NG4memcpy M7memcpy Delta ((B-A)/A)*100
(Avg.Ticks A) (Avg.Ticks B) (latency reduction)
3 20 19 -5
7 29 27 -6.89
32 30 28 -6.66
128 89 69 -22.47
256 142 143 0.70
512 341 283 -17.00
1024 1588 655 -58.75
2048 3553 1357 -61.80
4096 7218 2590 -64.11
8192 13701 5231 -61.82
16384 28304 10716 -62.13
32768 56516 22995 -59.31
65536 115443 50840 -55.96

3. Memset numbers(un-aligned memset)

No.of bytes NG4memset M7memset Delta ((B-A)/A)*100
(Avg.Ticks A) (Avg.Ticks B) (latency reduction)
3 40 31 -22.5
7 52 29 -44.2307692308
32 89 86 -3.3707865169
128 201 74 -63.184079602
256 340 154 -54.7058823529
512 961 335 -65.1404786681
1024 1799 686 -61.8677042802
2048 3575 1260 -64.7552447552
4096 6560 2627 -59.9542682927
8192 13161 6018 -54.273991338
16384 26465 10439 -60.5554505951
32768 52119 18649 -64.2184232238
65536 101593 35724 -64.8361599717

4. Memcpy numbers(un-aligned memcpy)

No.of bytes NG4memcpy M7memcpy Delta ((B-A)/A)*100
(Avg.Ticks A) (Avg.Ticks B) (latency reduction)
3 26 19 -26.9230769231
7 48 45 -6.25
32 52 49 -5.7692307692
128 284 334 17.6056338028
256 430 482 12.0930232558
512 646 690 6.8111455108
1024 1051 1016 -3.3301617507
2048 1787 1818 1.7347509793
4096 3309 3376 2.0247809006
8192 8151 7444 -8.673782358
16384 34222 34556 0.9759803635
32768 87851 95044 8.1877269468
65536 158331 159572 0.7838010244

There is not much difference in numbers with Un-aligned copies
between NG4memcpy and M7memcpy because they both mostly use the
same algorithems.

v2:
1. Fixed indentation issues found by David Miller
2. Used ENTRY and ENDPROC for the labels in M7patch.S as suggested by David Miller
3. Now M8 also will use M7memcpy. Also tested on M8 config.
4. These patches are created on top of below M8 patches
https://patchwork.ozlabs.org/patch/792661/
https://patchwork.ozlabs.org/patch/792662/
However, I did not see these patches in sparc-next tree. It may be in queue now.
It is possible these patches might cause some build problems. It will resolve
once all M8 patches are in sparc-next tree.

v0: Initial version

Babu Moger (4):
arch/sparc: Separate the exception handlers from NG4memcpy
arch/sparc: Rename exception handlers
arch/sparc: Optimized memcpy, memset, copy_to_user, copy_from_user
for M7/M8
arch/sparc: Add accurate exception reporting in M7memcpy

arch/sparc/kernel/head_64.S | 16 +-
arch/sparc/lib/M7copy_from_user.S | 40 ++
arch/sparc/lib/M7copy_to_user.S | 51 ++
arch/sparc/lib/M7memcpy.S | 923 +++++++++++++++++++++++++++++++++++++
arch/sparc/lib/M7memset.S | 352 ++++++++++++++
arch/sparc/lib/M7patch.S | 51 ++
arch/sparc/lib/Makefile | 5 +
arch/sparc/lib/Memcpy_utils.S | 345 ++++++++++++++
arch/sparc/lib/NG4memcpy.S | 277 +++---------
9 files changed, 1845 insertions(+), 215 deletions(-)
create mode 100644 arch/sparc/lib/M7copy_from_user.S
create mode 100644 arch/sparc/lib/M7copy_to_user.S
create mode 100644 arch/sparc/lib/M7memcpy.S
create mode 100644 arch/sparc/lib/M7memset.S
create mode 100644 arch/sparc/lib/M7patch.S
create mode 100644 arch/sparc/lib/Memcpy_utils.S