[PATCH] Remove HAVE_VIRT_CPU_ACCOUNTING_GEN option

Nicholas Piggin
2023-04-29T06:34:24Z

This option was created in commit 554b0004d0ec4 ("vtime: Add
HAVE_VIRT_CPU_ACCOUNTING_GEN Kconfig") for architectures to indicate
they support the 64-bit cputime_t required for VIRT_CPU_ACCOUNTING_GEN.

The cputime_t type has since been removed, so this doesn't have any
meaning. Remove it.

Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: linux-snps-arc@lists.infradead.org
Cc: Brian Cain <bcain@quicinc.com>
Cc: linux-hexagon@vger.kernel.org
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: loongarch@lists.linux.dev
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-m68k@lists.linux-m68k.org
Cc: Michal Simek <monstr@monstr.eu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: linux-mips@vger.kernel.org
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: linux-openrisc@vger.kernel.org
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: linux-riscv@lists.infradead.org
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: linux-sh@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: linux-um@lists.infradead.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
Hi,

Could we tidy this? I don't know what tree it can go in, timers,
sched, asm-generic, probably doesn't matter.

The only thing this actually does is gate VIRT_CPU_ACCOUNTING_GEN and
NO_HZ_FULL so if your arch has some other issue that requires this
then the documentation needs to change. Any concerns from the archs?
I.e., 32-bit that does *not* define HAVE_VIRT_CPU_ACCOUNTING_GEN
which looks to be:

arc
hexagon
loongarch 32-bit with SMP
m68k
microblaze
mips 32-bit with SMP
nios2
openrisc
parisc 32-bit
riscv 32-bit
sh
sparc 32-bit
um 32-bit
x86 32-bit

Thanks,
Nick
--
arch/Kconfig | 11 -----------
arch/arm/Kconfig | 1 -
arch/csky/Kconfig | 1 -
arch/loongarch/Kconfig | 1 -
arch/mips/Kconfig | 1 -
arch/powerpc/Kconfig | 1 -
arch/xtensa/Kconfig | 1 -
init/Kconfig | 1 -
kernel/time/Kconfig | 2 --
9 files changed, 20 deletions(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index 205fd23e0cad..b77b41d25e40 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -869,17 +869,6 @@ config HAVE_VIRT_CPU_ACCOUNTING_IDLE
config ARCH_HAS_SCALED_CPUTIME
bool

-config HAVE_VIRT_CPU_ACCOUNTING_GEN
- bool
- default y if 64BIT
- help
- With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit.
- Before enabling this option, arch code must be audited
- to ensure there are no races in concurrent read/write of
- cputime_t. For example, reading/writing 64-bit cputime_t on
- some 32-bit arches may require multiple accesses, so proper
- locking is needed to protect against concurrent accesses.
-
config HAVE_IRQ_TIME_ACCOUNTING
bool
help
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 0fb4b218f665..9c05f25db4e4 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -123,7 +123,6 @@ config ARM
select HAVE_STACKPROTECTOR
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_UID16
- select HAVE_VIRT_CPU_ACCOUNTING_GEN
select IRQ_FORCED_THREADING
select MODULES_USE_ELF_REL
select NEED_DMA_MAP_STATE
diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
index 00379a843c37..dd1decc2a22d 100644
--- a/arch/csky/Kconfig
+++ b/arch/csky/Kconfig
@@ -73,7 +73,6 @@ config CSKY
select HAVE_ARCH_MMAP_RND_BITS
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_CONTEXT_TRACKING_USER
- select HAVE_VIRT_CPU_ACCOUNTING_GEN
select HAVE_DEBUG_BUGVERBOSE
select HAVE_DEBUG_KMEMLEAK
select HAVE_DYNAMIC_FTRACE
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index f44f6ea54e46..7dc71c89bfae 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -122,7 +122,6 @@ config LOONGARCH
select HAVE_STACKPROTECTOR
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_TIF_NOHZ
- select HAVE_VIRT_CPU_ACCOUNTING_GEN if !SMP
select IRQ_FORCED_THREADING
select IRQ_LOONGARCH_CPU
select MMU_GATHER_MERGE_VMAS if MMU
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index c2f5498d207f..d84cb8bbee53 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -87,7 +87,6 @@ config MIPS
select HAVE_SPARSE_SYSCALL_NR
select HAVE_STACKPROTECTOR
select HAVE_SYSCALL_TRACEPOINTS
- select HAVE_VIRT_CPU_ACCOUNTING_GEN if 64BIT || !SMP
select IRQ_FORCED_THREADING
select ISA if EISA
select MODULES_USE_ELF_REL if MODULES
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index acffffbd5d77..185195f349d9 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -271,7 +271,6 @@ config PPC
select HAVE_STATIC_CALL if PPC32
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_VIRT_CPU_ACCOUNTING
- select HAVE_VIRT_CPU_ACCOUNTING_GEN
select HUGETLB_PAGE_SIZE_VARIABLE if PPC_BOOK3S_64 && HUGETLB_PAGE
select IOMMU_HELPER if PPC64
select IRQ_DOMAIN
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 3c6e5471f025..04f1399d9ce8 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -47,7 +47,6 @@ config XTENSA
select HAVE_PERF_EVENTS
select HAVE_STACKPROTECTOR
select HAVE_SYSCALL_TRACEPOINTS
- select HAVE_VIRT_CPU_ACCOUNTING_GEN
select IRQ_DOMAIN
select MODULES_USE_ELF_RELA
select PERF_USE_VMALLOC
diff --git a/init/Kconfig b/init/Kconfig
index 32c24950c4ce..835fb5e78a8f 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -504,7 +504,6 @@ config VIRT_CPU_ACCOUNTING_NATIVE
config VIRT_CPU_ACCOUNTING_GEN
bool "Full dynticks CPU time accounting"
depends on HAVE_CONTEXT_TRACKING_USER
- depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
depends on GENERIC_CLOCKEVENTS
select VIRT_CPU_ACCOUNTING
select CONTEXT_TRACKING_USER
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index bae8f11070be..d4325dae1f03 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -121,8 +121,6 @@ config NO_HZ_FULL
# We need at least one periodic CPU for timekeeping
depends on SMP
depends on HAVE_CONTEXT_TRACKING_USER
- # VIRT_CPU_ACCOUNTING_GEN dependency
- depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
select NO_HZ_COMMON
select RCU_NOCB_CPU
select VIRT_CPU_ACCOUNTING_GEN
--
2.40.1