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Alexei Starovoitov f696b8f471 bpf: split bpf core interpreter
split __bpf_prog_run() interpreter into stack allocation and execution parts.
The code section shrinks which helps interpreter performance in some cases.
   text	   data	    bss	    dec	    hex	filename
  26350	  10328	    624	  37302	   91b6	kernel/bpf/core.o.before
  25777	  10328	    624	  36729	   8f79	kernel/bpf/core.o.after

Very short programs got slower (due to extra function call):
Before:
test_bpf: #89 ALU64_ADD_K: 1 + 2 = 3 jited:0 7 PASS
test_bpf: #90 ALU64_ADD_K: 3 + 0 = 3 jited:0 8 PASS
test_bpf: #91 ALU64_ADD_K: 1 + 2147483646 = 2147483647 jited:0 7 PASS
test_bpf: #92 ALU64_ADD_K: 4294967294 + 2 = 4294967296 jited:0 11 PASS
test_bpf: #93 ALU64_ADD_K: 2147483646 + -2147483647 = -1 jited:0 7 PASS
After:
test_bpf: #89 ALU64_ADD_K: 1 + 2 = 3 jited:0 11 PASS
test_bpf: #90 ALU64_ADD_K: 3 + 0 = 3 jited:0 11 PASS
test_bpf: #91 ALU64_ADD_K: 1 + 2147483646 = 2147483647 jited:0 11 PASS
test_bpf: #92 ALU64_ADD_K: 4294967294 + 2 = 4294967296 jited:0 14 PASS
test_bpf: #93 ALU64_ADD_K: 2147483646 + -2147483647 = -1 jited:0 10 PASS

Longer programs got faster:
Before:
test_bpf: #266 BPF_MAXINSNS: Ctx heavy transformations jited:0 20286 20513 PASS
test_bpf: #267 BPF_MAXINSNS: Call heavy transformations jited:0 31853 31768 PASS
test_bpf: #268 BPF_MAXINSNS: Jump heavy test jited:0 9815 PASS
test_bpf: #269 BPF_MAXINSNS: Very long jump backwards jited:0 6 PASS
test_bpf: #270 BPF_MAXINSNS: Edge hopping nuthouse jited:0 13959 PASS
test_bpf: #271 BPF_MAXINSNS: Jump, gap, jump, ... jited:0 210 PASS
test_bpf: #272 BPF_MAXINSNS: ld_abs+get_processor_id jited:0 21724 PASS
test_bpf: #273 BPF_MAXINSNS: ld_abs+vlan_push/pop jited:0 19118 PASS
After:
test_bpf: #266 BPF_MAXINSNS: Ctx heavy transformations jited:0 19008 18827 PASS
test_bpf: #267 BPF_MAXINSNS: Call heavy transformations jited:0 29238 28450 PASS
test_bpf: #268 BPF_MAXINSNS: Jump heavy test jited:0 9485 PASS
test_bpf: #269 BPF_MAXINSNS: Very long jump backwards jited:0 12 PASS
test_bpf: #270 BPF_MAXINSNS: Edge hopping nuthouse jited:0 13257 PASS
test_bpf: #271 BPF_MAXINSNS: Jump, gap, jump, ... jited:0 213 PASS
test_bpf: #272 BPF_MAXINSNS: ld_abs+get_processor_id jited:0 19389 PASS
test_bpf: #273 BPF_MAXINSNS: ld_abs+vlan_push/pop jited:0 19583 PASS

For real world production programs the difference is noise.

This patch is first step towards reducing interpreter stack consumption.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-31 19:29:47 -04:00
arch bpf: free up BPF_JMP | BPF_CALL | BPF_X opcode 2017-05-31 19:29:47 -04:00
block Merge branch 'nvme-4.12' of git://git.infradead.org/nvme into for-linus 2017-05-26 09:11:19 -06:00
certs scripts/spelling.txt: add "intialise(d)" pattern and fix typo instances 2017-05-08 17:15:13 -07:00
crypto crypto: skcipher - Add missing API setkey checks 2017-05-18 13:04:05 +08:00
Documentation dt-bindings: qca7000: append UART interface to binding 2017-05-30 13:57:32 -04:00
drivers nfp: fix memory leak on FW load error 2017-05-31 17:58:13 -04:00
firmware firmware/Makefile: force recompilation if makefile changes 2017-05-08 17:15:10 -07:00
fs Changed since last update: 2017-05-26 12:13:08 -07:00
include bpf: free up BPF_JMP | BPF_CALL | BPF_X opcode 2017-05-31 19:29:47 -04:00
init Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-05-10 10:30:46 -07:00
ipc mm: introduce kv[mz]alloc helpers 2017-05-08 17:15:12 -07:00
kernel bpf: split bpf core interpreter 2017-05-31 19:29:47 -04:00
lib test_bpf: Add a couple of tests for BPF_JSGE. 2017-05-25 14:37:56 -04:00
mm mm: vmscan: scan until it finds eligible pages 2017-05-12 15:57:16 -07:00
net rtnetlink: use the new rtnl_get_event() interface 2017-05-31 13:08:36 -04:00
samples samples/bpf: bpf_load.c order of prog_fd[] should correspond with ELF order 2017-05-31 12:59:20 -04:00
scripts DeviceTree fixes for 4.12-rc: 2017-05-19 15:03:24 -07:00
security Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-05-09 09:12:53 -07:00
sound sound fixes for 4.12-rc3 2017-05-26 09:03:09 -07:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-05-26 20:46:35 -04:00
usr initramfs: provide a way to ignore image provided by bootloader 2017-05-08 17:15:12 -07:00
virt KVM: arm/arm64: Hold slots_lock when unregistering kvm io bus devices 2017-05-18 11:18:16 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support to generate LLVM assembly files 2017-04-25 08:13:52 +09:00
.mailmap power supply and reset changes for the v4.12 series (part 2) 2017-05-12 12:02:21 -07:00
COPYING
CREDITS avr32: remove support for AVR32 architecture 2017-05-01 09:27:15 +02:00
Kbuild kbuild: Consolidate header generation from ASM offset information 2017-04-13 05:43:37 +09:00
Kconfig
MAINTAINERS Add the mlxfw module for Mellanox firmware flash process 2017-05-25 17:46:17 -04:00
Makefile Linux 4.12-rc2 2017-05-21 19:30:23 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.