Open11
「試して理解 Linuxのしくみ」の読書録
yuji38kwmt
実行環境
- Thinkpad X220
- XUbuntu 20.04
$ uname -a
Linux yuji-ThinkPad-X220 5.4.0-121-generic #137-Ubuntu SMP Wed Jun 15 13:33:07 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
yuji@yuji-ThinkPad-X220:~$
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04.4 LTS
Release: 20.04
Codename: focal
$ sudo lshw -class processor
[sudo] yuji のパスワード:
*-cpu
詳細: CPU
製品: Intel(R) Core(TM) i7-2640M CPU @ 2.80GHz
ベンダー: Intel Corp.
物理ID: 1
バス情報: cpu@0
バージョン: Intel(R) Core(TM) i7-2640M CPU @ 2.80GHz
シリアル: Not Supported by CPU
スロット: CPU
サイズ: 974MHz
容量: 3500MHz
幅: 64 bits
クロック: 100MHz
性能: lm fpu fpu_exception wp vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ht tm pbe syscall nx rdtscp x86-64 constant_tsc arch_perfmon pebs bts nopl xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx lahf_lm epb pti ssbd ibrs ibpb stibp tpr_shadow vnmi flexpriority ept vpid xsaveopt dtherm ida arat pln pts md_clear flush_l1d cpufreq
設定: cores=2 enabledcores=2 threads=4
$ sudo lshw
*-memory
詳細: システムメモリー
物理ID: 5
スロット: システムボードまたはマザーボード
サイズ: 8GiB
*-bank:0
詳細: SODIMM DDR3 同期 1333 MHz (0.8 ns)
製品: M471B5273DH0-CH9
ベンダー: Samsung
物理ID: 0
シリアル: xxx
スロット: ChannelA-DIMM0
サイズ: 4GiB
幅: 64 bits
クロック: 1333MHz (0.8ns)
*-bank:1
詳細: SODIMM DDR3 同期 1333 MHz (0.8 ns)
製品: HYF3A1C167HZ3
ベンダー: Fujitsu
物理ID: 1
シリアル: xxx
スロット: ChannelB-DIMM0
サイズ: 4GiB
幅: 64 bits
クロック: 1333MHz (0.8ns)
*-scsi
物理ID: 8
論理名: scsi0
性能: emulated
*-disk
詳細: ATA Disk
製品: HITACHI HTS54323
ベンダー: Hitachi
物理ID: 0.0.0
バス情報: scsi@0:0.0.0
論理名: /dev/sda
バージョン: B70T
シリアル: xxx
サイズ: 298GiB (320GB)
性能: partitioned partitioned:dos
設定: ansiversion=5 logicalsectorsize=512 sectorsize=512 signature=64e8f38e
*-volume:0
詳細: EXT4ボリューム
ベンダー: Linux
物理ID: 1
バス情報: scsi@0:0.0.0,1
論理名: /dev/sda1
論理名: /
バージョン: 1.0
シリアル: xxx
サイズ: 290GiB
容量: 290GiB
性能: primary bootable journaled extended_attributes large_files huge_files dir_nlink extents ext4 ext2 initialized
設定: created=2022-06-30 08:20:43 filesystem=ext4 lastmountpoint=/ modified=2022-07-10 22:21:05 mount.fstype=ext4 mount.options=rw,relatime,errors=remount-ro mounted=2022-07-10 15:26:09 state=mounted
*-volume:1
詳細: Extended partition
物理ID: 2
バス情報: scsi@0:0.0.0,2
論理名: /dev/sda2
サイズ: 8074MiB
容量: 8074MiB
性能: primary extended partitioned partitioned:extended
*-logicalvolume
詳細: Linux swap ボリューム
物理ID: 5
論理名: /dev/sda5
バージョン: 1
シリアル: xxx
サイズ: 8074MiB
容量: 8074MiB
性能: nofs swap initialized
設定: filesystem=swap pagesize=4096
2章
システムコールの呼び出し
hello.cのシステムコール
$ cat hello.log
execve("./hello", ["./hello"], 0x7ffd860dbe80 /* 53 vars */) = 0
brk(NULL) = 0x55cec6926000
arch_prctl(0x3001 /* ARCH_??? */, 0x7ffe6d1b5c50) = -1 EINVAL (無効な引数です)
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (そのようなファイルやディレクトリはありません)
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=84453, ...}) = 0
mmap(NULL, 84453, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f09546e0000
close(3) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\300A\2\0\0\0\0\0"..., 832) = 832
pread64(3, "\6\0\0\0\4\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0"..., 784, 64) = 784
pread64(3, "\4\0\0\0\20\0\0\0\5\0\0\0GNU\0\2\0\0\300\4\0\0\0\3\0\0\0\0\0\0\0", 32, 848) = 32
pread64(3, "\4\0\0\0\24\0\0\0\3\0\0\0GNU\0\30x\346\264ur\f|Q\226\236i\253-'o"..., 68, 880) = 68
fstat(3, {st_mode=S_IFREG|0755, st_size=2029592, ...}) = 0
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f09546de000
pread64(3, "\6\0\0\0\4\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0"..., 784, 64) = 784
pread64(3, "\4\0\0\0\20\0\0\0\5\0\0\0GNU\0\2\0\0\300\4\0\0\0\3\0\0\0\0\0\0\0", 32, 848) = 32
pread64(3, "\4\0\0\0\24\0\0\0\3\0\0\0GNU\0\30x\346\264ur\f|Q\226\236i\253-'o"..., 68, 880) = 68
mmap(NULL, 2037344, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f09544ec000
mmap(0x7f095450e000, 1540096, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x22000) = 0x7f095450e000
mmap(0x7f0954686000, 319488, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x19a000) = 0x7f0954686000
mmap(0x7f09546d4000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1e7000) = 0x7f09546d4000
mmap(0x7f09546da000, 13920, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f09546da000
close(3) = 0
arch_prctl(ARCH_SET_FS, 0x7f09546df540) = 0
mprotect(0x7f09546d4000, 16384, PROT_READ) = 0
mprotect(0x55cec4acb000, 4096, PROT_READ) = 0
mprotect(0x7f0954722000, 4096, PROT_READ) = 0
munmap(0x7f09546e0000, 84453) = 0
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(0x88, 0x3), ...}) = 0
brk(NULL) = 0x55cec6926000
brk(0x55cec6947000) = 0x55cec6947000
write(1, "hello world\n", 12) = 12
exit_group(0) = ?
+++ exited with 0 +++
P16 hello.pyのシステムコール
$ strace -o hello.py.log python3 hello.py
$ wc -l hello.py.log
519 hello.py.log
$ tail hello.py.log
lseek(3, 0, SEEK_SET) = 0
read(3, "print(\"hello world\")\n", 4096) = 21
read(3, "", 4096) = 0
close(3) = 0
write(1, "hello world\n", 12) = 12
rt_sigaction(SIGINT, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7ffa37770090}, {sa_handler=0x6290b0, sa_mask=[], sa_flags=SA_RESTORER, sa_restorer=0x7ffa37770090}, 8) = 0
sigaltstack(NULL, {ss_sp=0x20e1440, ss_flags=0, ss_size=16384}) = 0
sigaltstack({ss_sp=NULL, ss_flags=SS_DISABLE, ss_size=0}, NULL) = 0
exit_group(0) = ?
+++ exited with 0 +++
loop.cの実行中の統計情報
yuji@yuji-ThinkPad-X220:~/Documents/study/linux-in-practice/02-syscall-and-non-kernel-os$ ./loop &
[1] 4264
yuji@yuji-ThinkPad-X220:~/Documents/study/linux-in-practice/02-syscall-and-non-kernel-os$ sar -P ALL 1
Linux 5.4.0-121-generic (yuji-ThinkPad-X220) 2022年07月10日 _x86_64_ (4 CPU)
22時57分23秒 CPU %user %nice %system %iowait %steal %idle
22時57分24秒 all 25.25 0.00 0.25 0.00 0.00 74.50
22時57分24秒 0 0.99 0.00 0.99 0.00 0.00 98.02
22時57分24秒 1 0.00 0.00 0.00 0.00 0.00 100.00
22時57分24秒 2 100.00 0.00 0.00 0.00 0.00 0.00
22時57分24秒 3 0.00 0.00 0.00 0.00 0.00 100.00
22時57分24秒 CPU %user %nice %system %iowait %steal %idle
22時57分25秒 all 25.00 0.00 0.00 0.00 0.00 75.00
22時57分25秒 0 0.00 0.00 0.00 0.00 0.00 100.00
22時57分25秒 1 0.00 0.00 0.00 0.00 0.00 100.00
22時57分25秒 2 100.00 0.00 0.00 0.00 0.00 0.00
22時57分25秒 3 0.00 0.00 0.00 0.00 0.00 100.00
ppidloop.cの統計情報
yuji@yuji-ThinkPad-X220:~/Documents/study/linux-in-practice/02-syscall-and-non-kernel-os$ ./ppiidloop &
[1] 4348
yuji@yuji-ThinkPad-X220:~/Documents/study/linux-in-practice/02-syscall-and-non-kernel-os$ sar -P ALL 1
Linux 5.4.0-121-generic (yuji-ThinkPad-X220) 2022年07月10日 _x86_64_ (4 CPU)
23時01分40秒 CPU %user %nice %system %iowait %steal %idle
23時01分41秒 all 14.93 0.00 10.95 0.00 0.00 74.13
23時01分41秒 0 0.98 0.00 0.98 0.00 0.00 98.04
23時01分41秒 1 0.00 0.00 1.00 0.00 0.00 99.00
23時01分41秒 2 58.00 0.00 42.00 0.00 0.00 0.00
23時01分41秒 3 1.00 0.00 0.00 0.00 0.00 99.00
23時01分41秒 CPU %user %nice %system %iowait %steal %idle
23時01分42秒 all 14.79 0.00 10.53 0.00 0.00 74.69
23時01分42秒 0 0.00 0.00 0.00 0.00 0.00 100.00
23時01分42秒 1 0.00 0.00 0.00 0.00 0.00 100.00
23時01分42秒 2 58.00 0.00 42.00 0.00 0.00 0.00
23時01分42秒 3 1.00 0.00 0.00 0.00 0.00 99.00
システムコール所要時間
$ strace -T ./hello
execve("./hello", ["./hello"], 0x7fffc3d420b8 /* 53 vars */) = 0 <0.000616>
brk(NULL) = 0x563869102000 <0.000042>
arch_prctl(0x3001 /* ARCH_??? */, 0x7ffc1852c8f0) = -1 EINVAL (無効な引数です) <0.000062>
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (そのようなファイルやディレクトリはありません) <0.000017>
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3 <0.000016>
fstat(3, {st_mode=S_IFREG|0644, st_size=84453, ...}) = 0 <0.000011>
mmap(NULL, 84453, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fe851e55000 <0.000013>
close(3) = 0 <0.000007>
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3 <0.000010>
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\300A\2\0\0\0\0\0"..., 832) = 832 <0.000008>
pread64(3, "\6\0\0\0\4\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0"..., 784, 64) = 784 <0.000007>
pread64(3, "\4\0\0\0\20\0\0\0\5\0\0\0GNU\0\2\0\0\300\4\0\0\0\3\0\0\0\0\0\0\0", 32, 848) = 32 <0.000007>
pread64(3, "\4\0\0\0\24\0\0\0\3\0\0\0GNU\0\30x\346\264ur\f|Q\226\236i\253-'o"..., 68, 880) = 68 <0.000007>
fstat(3, {st_mode=S_IFREG|0755, st_size=2029592, ...}) = 0 <0.000007>
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe851e53000 <0.000008>
pread64(3, "\6\0\0\0\4\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0"..., 784, 64) = 784 <0.000007>
pread64(3, "\4\0\0\0\20\0\0\0\5\0\0\0GNU\0\2\0\0\300\4\0\0\0\3\0\0\0\0\0\0\0", 32, 848) = 32 <0.000007>
pread64(3, "\4\0\0\0\24\0\0\0\3\0\0\0GNU\0\30x\346\264ur\f|Q\226\236i\253-'o"..., 68, 880) = 68 <0.000007>
mmap(NULL, 2037344, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fe851c61000 <0.000008>
mmap(0x7fe851c83000, 1540096, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x22000) = 0x7fe851c83000 <0.000015>
mmap(0x7fe851dfb000, 319488, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x19a000) = 0x7fe851dfb000 <0.000012>
mmap(0x7fe851e49000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1e7000) = 0x7fe851e49000 <0.000012>
mmap(0x7fe851e4f000, 13920, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7fe851e4f000 <0.000011>
close(3) = 0 <0.000007>
arch_prctl(ARCH_SET_FS, 0x7fe851e54540) = 0 <0.000008>
mprotect(0x7fe851e49000, 16384, PROT_READ) = 0 <0.000011>
mprotect(0x563868bb6000, 4096, PROT_READ) = 0 <0.000009>
mprotect(0x7fe851e97000, 4096, PROT_READ) = 0 <0.000009>
munmap(0x7fe851e55000, 84453) = 0 <0.000021>
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(0x88, 0), ...}) = 0 <0.000007>
brk(NULL) = 0x563869102000 <0.000007>
brk(0x563869123000) = 0x563869123000 <0.000008>
write(1, "hello world\n", 12hello world
) = 12 <0.000012>
exit_group(0) = ?
+++ exited with 0 +++
lddコマンドでどのライブラリをリンクしているか調べる
$ ldd /bin/echo
linux-vdso.so.1 (0x00007ffc7b864000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f68ebcf5000)
/lib64/ld-linux-x86-64.so.2 (0x00007f68ebf09000)
$ ldd /usr/bin/python3
linux-vdso.so.1 (0x00007ffe2ebcf000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f125f8cc000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f125f8a9000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f125f8a3000)
libutil.so.1 => /lib/x86_64-linux-gnu/libutil.so.1 (0x00007f125f89e000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f125f74f000)
libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007f125f721000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f125f703000)
/lib64/ld-linux-x86-64.so.2 (0x00007f125fad5000)
P34 エントリポイント
$ readelf -h /bin/sleep
ELF ヘッダ:
マジック: 7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00
クラス: ELF64
データ: 2 の補数、リトルエンディアン
Version: 1 (current)
OS/ABI: UNIX - System V
ABI バージョン: 0
型: DYN (共有オブジェクトファイル)
マシン: Advanced Micro Devices X86-64
バージョン: 0x1
エントリポイントアドレス: 0x2850
プログラムヘッダ始点: 64 (バイト)
セクションヘッダ始点: 37336 (バイト)
フラグ: 0x0
Size of this header: 64 (bytes)
Size of program headers: 56 (bytes)
Number of program headers: 13
Size of section headers: 64 (bytes)
Number of section headers: 30
Section header string table index: 29
$ readelf -S /bin/sleep
There are 30 section headers, starting at offset 0x91d8:
セクションヘッダ:
[番] 名前 タイプ アドレス オフセット
サイズ EntSize フラグ Link 情報 整列
[ 0] NULL 0000000000000000 00000000
0000000000000000 0000000000000000 0 0 0
[ 1] .interp PROGBITS 0000000000000318 00000318
000000000000001c 0000000000000000 A 0 0 1
[ 2] .note.gnu.propert NOTE 0000000000000338 00000338
0000000000000020 0000000000000000 A 0 0 8
[ 3] .note.gnu.build-i NOTE 0000000000000358 00000358
0000000000000024 0000000000000000 A 0 0 4
[ 4] .note.ABI-tag NOTE 000000000000037c 0000037c
0000000000000020 0000000000000000 A 0 0 4
[ 5] .gnu.hash GNU_HASH 00000000000003a0 000003a0
00000000000000a8 0000000000000000 A 6 0 8
[ 6] .dynsym DYNSYM 0000000000000448 00000448
0000000000000600 0000000000000018 A 7 1 8
[ 7] .dynstr STRTAB 0000000000000a48 00000a48
000000000000031f 0000000000000000 A 0 0 1
[ 8] .gnu.version VERSYM 0000000000000d68 00000d68
0000000000000080 0000000000000002 A 6 0 2
[ 9] .gnu.version_r VERNEED 0000000000000de8 00000de8
0000000000000060 0000000000000000 A 7 1 8
[10] .rela.dyn RELA 0000000000000e48 00000e48
00000000000002b8 0000000000000018 A 6 0 8
[11] .rela.plt RELA 0000000000001100 00001100
00000000000003f0 0000000000000018 AI 6 25 8
[12] .init PROGBITS 0000000000002000 00002000
000000000000001b 0000000000000000 AX 0 0 4
[13] .plt PROGBITS 0000000000002020 00002020
00000000000002b0 0000000000000010 AX 0 0 16
[14] .plt.got PROGBITS 00000000000022d0 000022d0
0000000000000010 0000000000000010 AX 0 0 16
[15] .plt.sec PROGBITS 00000000000022e0 000022e0
00000000000002a0 0000000000000010 AX 0 0 16
[16] .text PROGBITS 0000000000002580 00002580
0000000000003692 0000000000000000 AX 0 0 16
[17] .fini PROGBITS 0000000000005c14 00005c14
000000000000000d 0000000000000000 AX 0 0 4
[18] .rodata PROGBITS 0000000000006000 00006000
0000000000000f6c 0000000000000000 A 0 0 32
[19] .eh_frame_hdr PROGBITS 0000000000006f6c 00006f6c
00000000000002b4 0000000000000000 A 0 0 4
[20] .eh_frame PROGBITS 0000000000007220 00007220
0000000000000d18 0000000000000000 A 0 0 8
[21] .init_array INIT_ARRAY 0000000000009bb0 00008bb0
0000000000000008 0000000000000008 WA 0 0 8
[22] .fini_array FINI_ARRAY 0000000000009bb8 00008bb8
0000000000000008 0000000000000008 WA 0 0 8
[23] .data.rel.ro PROGBITS 0000000000009bc0 00008bc0
00000000000000b8 0000000000000000 WA 0 0 32
[24] .dynamic DYNAMIC 0000000000009c78 00008c78
00000000000001f0 0000000000000010 WA 7 0 8
[25] .got PROGBITS 0000000000009e68 00008e68
0000000000000190 0000000000000008 WA 0 0 8
[26] .data PROGBITS 000000000000a000 00009000
0000000000000080 0000000000000000 WA 0 0 32
[27] .bss NOBITS 000000000000a080 00009080
00000000000001b8 0000000000000000 WA 0 0 32
[28] .gnu_debuglink PROGBITS 0000000000000000 00009080
0000000000000034 0000000000000000 0 0 4
[29] .shstrtab STRTAB 0000000000000000 000090b4
000000000000011d 0000000000000000 0 0 1
Key to Flags:
W (write), A (alloc), X (execute), M (merge), S (strings), I (info),
L (link order), O (extra OS processing required), G (group), T (TLS),
C (compressed), x (unknown), o (OS specific), E (exclude),
l (large), p (processor specific)
yuji@yuji-ThinkPad-X220:~$ /bin/sleep 10000 &
[1] 2060
yuji@yuji-ThinkPad-X220:~$ cat /proc/2060/maps
55ab8b13e000-55ab8b140000 r--p 00000000 08:01 3408056 /bin/sleep
55ab8b140000-55ab8b144000 r-xp 00002000 08:01 3408056 /bin/sleep
55ab8b144000-55ab8b146000 r--p 00006000 08:01 3408056 /bin/sleep
55ab8b147000-55ab8b148000 r--p 00008000 08:01 3408056 /bin/sleep
55ab8b148000-55ab8b149000 rw-p 00009000 08:01 3408056 /bin/sleep
55ab8b6f7000-55ab8b718000 rw-p 00000000 00:00 0 [heap]
7f422607e000-7f42266f1000 r--p 00000000 08:01 14418418 /usr/lib/locale/locale-archive
7f42266f1000-7f4226713000 r--p 00000000 08:01 13631590 /lib/x86_64-linux-gnu/libc-2.31.so
7f4226713000-7f422688b000 r-xp 00022000 08:01 13631590 /lib/x86_64-linux-gnu/libc-2.31.so
7f422688b000-7f42268d9000 r--p 0019a000 08:01 13631590 /lib/x86_64-linux-gnu/libc-2.31.so
7f42268d9000-7f42268dd000 r--p 001e7000 08:01 13631590 /lib/x86_64-linux-gnu/libc-2.31.so
7f42268dd000-7f42268df000 rw-p 001eb000 08:01 13631590 /lib/x86_64-linux-gnu/libc-2.31.so
7f42268df000-7f42268e5000 rw-p 00000000 00:00 0
7f42268fa000-7f42268fb000 r--p 00000000 08:01 13631515 /lib/x86_64-linux-gnu/ld-2.31.so
7f42268fb000-7f422691e000 r-xp 00001000 08:01 13631515 /lib/x86_64-linux-gnu/ld-2.31.so
7f422691e000-7f4226926000 r--p 00024000 08:01 13631515 /lib/x86_64-linux-gnu/ld-2.31.so
7f4226927000-7f4226928000 r--p 0002c000 08:01 13631515 /lib/x86_64-linux-gnu/ld-2.31.so
7f4226928000-7f4226929000 rw-p 0002d000 08:01 13631515 /lib/x86_64-linux-gnu/ld-2.31.so
7f4226929000-7f422692a000 rw-p 00000000 00:00 0
7fff27c6d000-7fff27c8e000 rw-p 00000000 00:00 0 [stack]
7fff27d84000-7fff27d87000 r--p 00000000 00:00 0 [vvar]
7fff27d87000-7fff27d88000 r-xp 00000000 00:00 0 [vdso]
ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0 [vsyscall]
char *args[] = { "/bin/echo", "hello" , NULL};
execve("/bin/echo", args, NULL);
なぜ argsの先頭に/bin/echoが必要？
yuji38kwmt- task_set: https://ysatoautonomous.github.io/jm-draft/man2html/util-linux/util-linux-2.34/draft/man1/taskset.1.html
- pid_t: https://www.wdic.org/w/TECH/pid_t
$ sar -q 1 1
Linux 5.4.0-121-generic (yuji-ThinkPad-X220) 2022年07月17日 _x86_64_ (4 CPU)
07時16分46秒 runq-sz plist-sz ldavg-1 ldavg-5 ldavg-15 blocked
07時16分47秒 1 685 0.82 0.39 0.29 0
平均値: 1 685 0.82 0.39 0.29 0
経過時間と使用時間
yuji@yuji-ThinkPad-X220:~/Documents/study/linux-in-practice/04-process-scheduler$ time taskset -c 0 ./sched 1 10000 10000
estimating the workload which takes just one milli-second...
end estimation
0 10412 100
real 0m12.691s
user 0m12.686s
sys 0m0.001s
yuji@yuji-ThinkPad-X220:~/Documents/study/linux-in-practice/04-process-scheduler$ time taskset -c 0 ./sched 2 10000 10000
estimating the workload which takes just one milli-second...
end estimation
1 21507 100
0 21513 100
real 0m23.787s
user 0m23.780s
sys 0m0.001s
yuji@yuji-ThinkPad-X220:~/Documents/study/linux-in-practice/04-process-scheduler$ time taskset -c 0,1 ./sched 1 10000 10000
estimating the workload which takes just one milli-second...
end estimation
0 10762 100
real 0m13.043s
user 0m13.035s
sys 0m0.004s
yuji@yuji-ThinkPad-X220:~/Documents/study/linux-in-practice/04-process-scheduler$ time taskset -c 0,1 ./sched 2 10000 10000
estimating the workload which takes just one milli-second...
end estimation
0 12943 100
1 13000 100
real 0m15.284s
user 0m28.214s
sys 0m0.004s
感想
- psコマンドのオプションがカオス。「〜と等しい」オプションが多い。
- chromeはプロセスが多い
- 共有メモリ？
- forkの値