Re: [PATCH v2 4/4] mm, arch: add generic implementation of pfn_valid() for FLATMEM
From: Conor Dooley <conor@kernel.org>
Date: 2023-01-31 18:55:43
Also in:
linux-alpha, linux-arch, linux-m68k, linux-mips, linux-mm, linux-riscv, linux-sh, linux-um, linuxppc-dev, lkml, loongarch, sparclinux
Hi Mike, On Tue, Jan 31, 2023 at 08:41:49PM +0200, Mike Rapoport wrote:
quoted hunk ↗ jump to hunk
On Tue, Jan 31, 2023 at 05:47:24PM +0000, Conor Dooley wrote:quoted
On Sun, Jan 29, 2023 at 02:42:35PM +0200, Mike Rapoport wrote:quoted
From: "Mike Rapoport (IBM)" <rppt@kernel.org> Every architecture that supports FLATMEM memory model defines its own version of pfn_valid() that essentially compares a pfn to max_mapnr. Use mips/powerpc version implemented as static inline as a generic implementation of pfn_valid() and drop its per-architecture definitions. Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Guo Ren <guoren@kernel.org> # csky Acked-by: Huacai Chen <redacted> # LoongArch Acked-by: Stafford Horne <shorne@gmail.com> # OpenRISCHmm, so this landed in linux-next today and I bisected a boot failure in my CI to it. However, I am not really sure if it is a real issue worth worrying about as the platform it triggered on is supposed to be using SPARSEMEM, but isn't. I had thought that my CI was using a config with SPARSEMEM since that became required for riscv defconfig builds to boot in v6.1-rc1, but I must have just forgotten to add it to my $platform_defconfig builds too. However, those $platform_defconfig builds continued booting without SPARSEMEM enabled until today.The issue seems to be that the generic pfn_valid() does not take into account pfn_offset when it compares it with max_mapnr. Can you please test with the patch below?diff --git a/include/asm-generic/memory_model.h b/include/asm-generic/memory_model.h index 13d2a844d928..6796abe1900e 100644 --- a/include/asm-generic/memory_model.h +++ b/include/asm-generic/memory_model.h@@ -26,7 +26,7 @@ static inline int pfn_valid(unsigned long pfn) extern unsigned long max_mapnr; unsigned long pfn_offset = ARCH_PFN_OFFSET; - return pfn >= pfn_offset && pfn < max_mapnr; + return pfn >= pfn_offset && (pfn - pfn_offset) < max_mapnr; } #define pfn_valid pfn_valid #endif
Gave that a go, board is booting properly again! Feel free to add a: Tested-by: Conor Dooley <conor.dooley@microchip.com> Thanks for the prompt fix!