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Date:   Sat, 29 Apr 2023 13:14:23 -0700 (PDT)
Subject:     Re: [PATCH] Remove HAVE_VIRT_CPU_ACCOUNTING_GEN option
In-Reply-To: <20230429063348.125544-1-npiggin@gmail.com>
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From:   Palmer Dabbelt <palmer@dabbelt.com>
To:     npiggin@gmail.com
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On Fri, 28 Apr 2023 23:33:48 PDT (-0700), npiggin@gmail.com wrote:
> 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

Nothing's jumping out, though I haven't tested this yet so I'm not 100%.  
I assume this isn't aimed for this merge window, given the timing?  
Probably best to give this sort of thing time to bake in linux-next, but 
I doubt anyone is even paying attention to rv32/NO_HZ_FULL so no big 
deal either way on my end.

Acked-by: Palmer Dabbelt <palmer@rivosinc.com> # RISC-V

> sh
> sparc 32-bit
> um 32-bit
> x86 32-bit
>
> Thanks,
> Nick