MYN - 2020/07/12 16:42 / Linux 5.8-rc4

2020/07/12 16:42 / Linux 5.8-rc4

Linux 5.8-rc1 がでたので(既に rc4 になってるけど)，5.7.8 から .configがどう変更されるのか見てみた．以下 - は削除されたもの，+ は追加されたもの．x86_64．New features 等は https://www.phoronix.com/scan.php?page=article&item=linux-58-features 参照．

追加

+CONFIG_ARCH_HAS_DEBUG_VM_PGTABLE=y

mm/debug: add tests validating architecture page table helpers

X86 で select される．CONFIG_DEBUG_VM_PGTABLE=y にすると有効になる．
+CONFIG_ARCH_HAS_DEBUG_WX=y

x86: mm: use ARCH_HAS_DEBUG_WX instead of arch defined
mm: add DEBUG_WX support

X86 で select される．v4.4 で導入された CONFIG_DEBUG_WX は arch/x86/Kconfig.debug から mm/Kconfig.debug に移動した．
+CONFIG_ARCH_USE_SYM_ANNOTATIONS=y

x86/asm: Provide a Kconfig symbol for disabling old assembly annotations

X86 で select される．
+CONFIG_AS_TPAUSE=y

x86/delay: Introduce TPAUSE delay

as が tpause 命令に対応していれば y になる．See https://www.phoronix.com/scan.php?page=news_item&px=Linux-5.8-Intel-TPAUSE.
+CONFIG_CC_CAN_LINK_STATIC=y

bpfilter: check if $(CC) can link static libc in Kconfig

cc が static link できれば y になる．CONFIG_BPFILTER_UMH が依存(←使ってない)．
+CONFIG_CC_HAS_WORKING_NOSANITIZE_ADDRESS=y

kasan: Bump required compiler version

CONFIG_KASAN (KASAN: runtime memory debugger)が依存．GCC 8 以上であれば y になる．

+CONFIG_CC_VERSION_TEXT="gcc (Debian 8.3.0-6) 8.3.0"

kbuild: ensure full rebuild when the compiler is updated

default は Makefile でチェックされる
`CC_VERSION_TEXT = $(shell $(CC) --version 2>/dev/null | head -n 1)`．
コンパイラが更新された場合に full build を行うため，とのこと．

+CONFIG_DEFAULT_INIT=""

init: allow distribution configuration of default init
+CONFIG_DRM_I915_FENCE_TIMEOUT=10000

drm/i915: Replace the hardcoded I915_FENCE_TIMEOUT

ハードコーディングされていたものを設定できるようになった(もとも10sまま)．
+CONFIG_DYNAMIC_DEBUG_CORE=y

dynamic_debug: add an option to enable dynamic debug for modules only

Module の Compile で dynamic debug の On/Off ができるように導入された．CONFIG_DYNAMIC_DEBUG で select される．Module compile の際に DYNAMIC_DEBUG_MODULE を define しておくと dynamic debug が有効になる．
```
This is useful for people who only want to enable dynamic debug for
kernel modules without worrying about kernel image size and memory
consumption is increasing too much.
```
とのこと．
+CONFIG_EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER=y

efi/libstub: Make initrd file loader configurable
efi/libstub: Re-enable command line initrd loading for x86

X86 で y になる．
+CONFIG_HAVE_ARCH_KCSAN=y

kcsan: Add Kernel Concurrency Sanitizer infrastructure

Kernel Concurrency Sanitizer (KCSAN) 関連．X86 で y になるが，CONFIG_KCSAN=y にするには CONFIG_HAVE_KCSAN_COMPILER が必要で，これは CC_IS_CLANG に依存する．
+CONFIG_HIBERNATION_SNAPSHOT_DEV=y

PM: hibernate: Split off snapshot dev option

y のままにしておく．
+CONFIG_TASKS_RCU_GENERIC=y
+CONFIG_TASKS_RUDE_RCU=y

rcu-tasks: Refactor RCU-tasks to allow variants to be added
rcu-tasks: Add an RCU-tasks rude variant

手元では FUNCTION_TRACER [=y] && TRACING_SUPPORT [=y] && FTRACE [=y] && HAVE_FUNCTION_TRACER [=y] で CONFIG_TASKS_RUDE_RCU=y になって，それに依存して CONFIG_TASKS_RCU_GENERIC=y に．

+CONFIG_XFRM_AH=m
+CONFIG_XFRM_ESP=m

esp, ah: consolidate the crypto algorithm selections

Instead of duplicating the algorithm selections between INET_AH and
INET6_AH and between INET_ESP and INET6_ESP, create new tristates
XFRM_AH and XFRM_ESP that do the algorithm selections, and make these be
selected by the corresponding INET* options.

とのこと．

`CONFIG_MEDIA_SUPPORT_FILTER` 関連

+CONFIG_DVB_CORE=m
+CONFIG_DVB_DYNAMIC_MINORS=y
+CONFIG_DVB_MAX_ADAPTERS=16
+CONFIG_DVB_NET=y
+CONFIG_MEDIA_ANALOG_TV_SUPPORT=y
+CONFIG_MEDIA_ATTACH=y
+CONFIG_MEDIA_DIGITAL_TV_SUPPORT=y
+CONFIG_MEDIA_PLATFORM_SUPPORT=y
+CONFIG_MEDIA_RADIO_SUPPORT=y
+CONFIG_MEDIA_SDR_SUPPORT=y
+CONFIG_MEDIA_TEST_SUPPORT=y
+CONFIG_MEDIA_TUNER=m
+CONFIG_MEDIA_TUNER_MC44S803=m
+CONFIG_MEDIA_TUNER_MT20XX=m
+CONFIG_MEDIA_TUNER_SIMPLE=m
+CONFIG_MEDIA_TUNER_TDA18271=m
+CONFIG_MEDIA_TUNER_TDA827X=m
+CONFIG_MEDIA_TUNER_TDA8290=m
+CONFIG_MEDIA_TUNER_TDA9887=m
+CONFIG_MEDIA_TUNER_TEA5761=m
+CONFIG_MEDIA_TUNER_TEA5767=m
+CONFIG_MEDIA_TUNER_XC2028=m
+CONFIG_MEDIA_TUNER_XC4000=m
+CONFIG_MEDIA_TUNER_XC5000=m
+CONFIG_RADIO_ADAPTERS=y

media: Kconfig: make filtering devices optional

自動的に選択されるようになった．
```
The per-device option selection is a feature that some
developers love, while others hate...

So, let's make both happy by making it optional.
```
とのこと．自動選択を無効にするには CONFIG_MEDIA_SUPPORT_FILTER=n とする．面倒なのでこのままにしてく．

削除

-CONFIG_DOUBLEFAULT=y

x86/32: Remove CONFIG_DOUBLEFAULT
-CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK=y

x86/entry: Use idtentry for interrupts

X86 (X86_64) で select されなくなった．
-CONFIG_HAVE_MEMBLOCK_NODE_MAP=y

mm: remove CONFIG_HAVE_MEMBLOCK_NODE_MAP option
-CONFIG_MEMCG_SWAP_ENABLED=y

mm: memcontrol: make swap tracking an integral part of memory control
-CONFIG_NODES_SPAN_OTHER_NODES=y

mm: remove early_pfn_in_nid() and CONFIG_NODES_SPAN_OTHER_NODES
-CONFIG_VHOST_DPN=y

vhost: revert “vhost: disable for OABI”

追記 (2020/8/21)

cachefiles の挙動が 5.8.x で怪しい．以下でコケる．5.6 でも cachefiles にはバグがあって，それは 5.6.14 で修正されたのだけど (Linux 5.6.x fs/cachefiles/rdwr.c bug参照)，そもそも cachefiles ユーザ(あるいは NFS ユーザ？)はそんなに多くないのかな．．．cachefiles 自体のコードは 5.7 から 5.8 でほぼ変更が加えられていない様子なのだけど．

Aug 21 19:14:42 qemu kernel: [  323.988885] CacheFiles: 
Aug 21 19:14:42 qemu kernel: [  323.988888] CacheFiles: Assertion failed
Aug 21 19:14:42 qemu kernel: [  323.988926] ------------[ cut here ]------------
Aug 21 19:14:42 qemu kernel: [  323.988927] kernel BUG at fs/cachefiles/rdwr.c:715!
Aug 21 19:14:42 qemu kernel: [  323.988934] invalid opcode: 0000 [#13] SMP PTI
Aug 21 19:14:42 qemu kernel: [  323.988937] CPU: 2 PID: 4214 Comm: sshd Tainted: P      D    O      5.8.2-20200821-diskless-01 #313
Aug 21 19:14:42 qemu kernel: [  323.988938] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1 04/01/2014
Aug 21 19:14:42 qemu kernel: [  323.988946] RIP: 0010:cachefiles_read_or_alloc_pages.cold.20+0x307/0x3b3 [cachefiles]
Aug 21 19:14:42 qemu kernel: [  323.988948] Code: 10 e8 69 db cc e0 48 8b 44 24 28 8b 10 e9 50 c2 ff ff 48 c7 c7 43 87 40 a0 e8 51 db cc e0 48 c7 c7 60 9d 40 a0 e8 45 db cc e0 <0f> 0b 49 8b 57 20 44 89 e9 48 c7 c7 e7 87 40 a0 65 48 8b 34 25 00
Aug 21 19:14:42 qemu kernel: [  323.988950] RSP: 0018:ffffc9000192f9c0 EFLAGS: 00010246
Aug 21 19:14:42 qemu kernel: [  323.988952] RAX: 000000000000001c RBX: ffff8881fbc8ac00 RCX: 0000000000000027
Aug 21 19:14:42 qemu kernel: [  323.988953] RDX: 0000000000000000 RSI: ffff88822be979c0 RDI: ffff88822be979c8
Aug 21 19:14:42 qemu kernel: [  323.988954] RBP: ffff8881dec0a068 R08: 0000000000000534 R09: 000000000000002b
Aug 21 19:14:42 qemu kernel: [  323.988955] R10: 0000000000000000 R11: ffffc9000192f875 R12: ffff8881c84dfa58
Aug 21 19:14:42 qemu kernel: [  323.988956] R13: ffffc9000192fcd0 R14: ffff888227a36900 R15: ffff8881dec0a000
Aug 21 19:14:42 qemu kernel: [  323.988958] FS:  00007f725f467e40(0000) GS:ffff88822be80000(0000) knlGS:0000000000000000
Aug 21 19:14:42 qemu kernel: [  323.988961] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Aug 21 19:14:42 qemu kernel: [  323.988963] CR2: 0000564ddd7d6168 CR3: 0000000187cfc000 CR4: 00000000000006e0
Aug 21 19:14:42 qemu kernel: [  323.988964] Call Trace:
Aug 21 19:14:42 qemu kernel: [  323.988971]  ? out_of_line_wait_on_bit+0x91/0xb0
Aug 21 19:14:42 qemu kernel: [  323.988976]  ? fscache_run_op.isra.12+0x55/0xb0
Aug 21 19:14:42 qemu kernel: [  323.988978]  __fscache_read_or_alloc_pages+0x28e/0x300
Aug 21 19:14:42 qemu kernel: [  323.988982]  __nfs_readpages_from_fscache+0x60/0x160
Aug 21 19:14:42 qemu kernel: [  323.988985]  nfs_readpages+0xb5/0x1a0
Aug 21 19:14:42 qemu kernel: [  323.988990]  read_pages+0x1c1/0x1f0
Aug 21 19:14:42 qemu kernel: [  323.988993]  page_cache_readahead_unbounded+0x1ad/0x200
Aug 21 19:14:42 qemu kernel: [  323.988997]  generic_file_buffered_read+0x5c3/0x960
Aug 21 19:14:42 qemu kernel: [  323.989001]  ? nfs4_do_check_delegation+0x18/0x40
Aug 21 19:14:42 qemu kernel: [  323.989005]  ? nfs_check_cache_invalid+0x33/0x90
Aug 21 19:14:42 qemu kernel: [  323.989007]  nfs_file_read+0x6b/0x90
Aug 21 19:14:42 qemu kernel: [  323.989011]  new_sync_read+0x114/0x1a0
Aug 21 19:14:42 qemu kernel: [  323.989013]  vfs_read+0x151/0x180
Aug 21 19:14:42 qemu kernel: [  323.989015]  ksys_read+0x59/0xd0
Aug 21 19:14:42 qemu kernel: [  323.989018]  do_syscall_64+0x3e/0xb0
Aug 21 19:14:42 qemu kernel: [  323.989020]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
Aug 21 19:14:42 qemu kernel: [  323.989023] RIP: 0033:0x7f725f80a461
Aug 21 19:14:42 qemu kernel: [  323.989025] Code: fe ff ff 50 48 8d 3d fe d0 09 00 e8 e9 03 02 00 66 0f 1f 84 00 00 00 00 00 48 8d 05 99 62 0d 00 8b 00 85 c0 75 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 57 c3 66 0f 1f 44 00 00 41 54 49 89 d4 55 48
Aug 21 19:14:42 qemu kernel: [  323.989026] RSP: 002b:00007ffd776e1588 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
Aug 21 19:14:42 qemu kernel: [  323.989028] RAX: ffffffffffffffda RBX: 0000564ddd7bdf90 RCX: 00007f725f80a461
Aug 21 19:14:42 qemu kernel: [  323.989029] RDX: 0000000000002000 RSI: 0000564ddd7d4160 RDI: 0000000000000004
Aug 21 19:14:42 qemu kernel: [  323.989030] RBP: 0000000000000d68 R08: 0000000000000003 R09: 00007f725f8dbd30
Aug 21 19:14:42 qemu kernel: [  323.989031] R10: 0000564ddd79e010 R11: 0000000000000246 R12: 00007f725f8d7760
Aug 21 19:14:42 qemu kernel: [  323.989032] R13: 00007f725f8d82a0 R14: 0000000000000000 R15: 0000000000000000
Aug 21 19:14:42 qemu kernel: [  323.989034] Modules linked in: fuse ext4 crc16 mbcache jbd2 dm_crypt ecb aes_generic libaes crypto_simd cryptd glue_helper xts algif_skcipher af_alg dm_mod xt_conntrack xt_MASQUERADE xfrm_user xfrm_algo nft_counter xt_addrtype nft_compat nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter cpufreq_userspace cpufreq_powersave cpufreq_ondemand cpufreq_conservative rpcsec_gss_krb5 btrfs blake2b_generic zstd_decompress zstd_compress bochs_drm drm_vram_helper drm_ttm_helper ttm drm_kms_helper syscopyarea intel_agp sysfillrect intel_gtt snd_pcm sg sysimgblt fb_sys_fops snd_timer joydev evdev snd serio_raw button soundcore pcspkr cachefiles lm78 i5k_amb nf_tables hwmon_vid nfnetlink msr drm agpgart nfsd binfmt_misc ip_tables x_tables autofs4 loop squashfs overlay raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sd_mod t10_pi crc_t10dif crct10dif_generic sr_mod cdrom crct10dif_common
Aug 21 19:14:42 qemu kernel: [  323.989066]  ata_generic ata_piix libata psmouse scsi_mod rtc_cmos
Aug 21 19:14:42 qemu kernel: [  323.989072] ---[ end trace f27e8415c423cf4c ]---
Aug 21 19:14:42 qemu kernel: [  323.989076] RIP: 0010:cachefiles_read_or_alloc_pages.cold.20+0x307/0x3b3 [cachefiles]
Aug 21 19:14:42 qemu kernel: [  323.989078] Code: 10 e8 69 db cc e0 48 8b 44 24 28 8b 10 e9 50 c2 ff ff 48 c7 c7 43 87 40 a0 e8 51 db cc e0 48 c7 c7 60 9d 40 a0 e8 45 db cc e0 <0f> 0b 49 8b 57 20 44 89 e9 48 c7 c7 e7 87 40 a0 65 48 8b 34 25 00
Aug 21 19:14:42 qemu kernel: [  323.989079] RSP: 0018:ffffc900005cf9c0 EFLAGS: 00010246
Aug 21 19:14:42 qemu kernel: [  323.989081] RAX: 000000000000001c RBX: ffff8881fbc8ac00 RCX: 0000000000000027
Aug 21 19:14:42 qemu kernel: [  323.989082] RDX: 0000000000000000 RSI: ffff88822bf179c0 RDI: ffff88822bf179c8
Aug 21 19:14:42 qemu kernel: [  323.989083] RBP: ffff8881dec0a068 R08: 000000000000027c R09: 000000000000002b
Aug 21 19:14:42 qemu kernel: [  323.989084] R10: 0000000000000000 R11: ffffc900005cf875 R12: ffff8881c84dfa58
Aug 21 19:14:42 qemu kernel: [  323.989085] R13: ffffc900005cfcd0 R14: ffff88822a584f00 R15: ffff8881dec0a000
Aug 21 19:14:42 qemu kernel: [  323.989086] FS:  00007f725f467e40(0000) GS:ffff88822be80000(0000) knlGS:0000000000000000
Aug 21 19:14:42 qemu kernel: [  323.989087] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Aug 21 19:14:42 qemu kernel: [  323.989088] CR2: 0000564ddd7d6168 CR3: 0000000187cfc000 CR4: 00000000000006e0

https://bugzilla.kernel.org/show_bug.cgi?id=208883 にも報告されていて，ここでは https://lkml.org/lkml/2020/8/3/960 の fscache-iterを merge すれば解決するという案が示されているが，https://lkml.org/lkml/2020/8/10/454でこの pull request は一旦取り下げられている．

追記 (2020/9/2)

cachefiles の挙動が 5.8.x で怪しい問題，https://lkml.org/lkml/2020/8/27/714 の patch をあてたら解決する．少なくとも 5.8.5 ではこの patch が必要．

追記 (2021/1/30)

cachefiles の挙動が怪しい問題，https://lkml.org/lkml/2020/8/27/714 の patch がようやく cachefiles: Drop superfluous readpages aops NULL checkのように取り込まれた様子．5.11-rc5 および 5.10.11 (commit)で修正されている．

追記 (2020/8/21)

以下の compile には https://gitlab.com/-/snippets/1986228/ のパッチが必要．

nvidia-kernel-dkms 440.100-1~bpo10+1
nvidia-legacy-390xx-kernel-dkms 390.138-1~deb10u1

また，nvidia-legacy-390xx-kernel-dkms については kernel 側に https://www.spinics.net/lists/linux-fsdevel/msg173844.html のパッチが必要(なぜか radix_tree_preloads が EXPORT_PER_CPU_SYMBOL_GPL されていてリンクできない，とかだったはず)．

やるきなし

2020/07/12 16:42 / Linux 5.8-rc4

追加

`CONFIG_MEDIA_SUPPORT_FILTER` 関連

削除

追記 (2020/8/21)

追記 (2020/9/2)

追記 (2021/1/30)

追記 (2020/8/21)

Related articles

2020/07/12 16:42 / Linux 5.8-rc4

追加

CONFIG_MEDIA_SUPPORT_FILTER 関連

削除

追記 (2020/8/21)

追記 (2020/9/2)

追記 (2021/1/30)

追記 (2020/8/21)

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`CONFIG_MEDIA_SUPPORT_FILTER` 関連