Changelog: v13: - Fixed a hang on ThunderX2, thank you Pingfan Liu for reporting the problem. In relocation function we need civac not ivac, we need to clean data in addition to invalidating it. Since I was using ThunderX2 machine I also measured the new performance data on this large ARM64 server. The MMU improves kexec relocation 190 times on this machine! (see below for raw data). Saves 7.5s during CentOS kexec reboot. v12: - A major change compared to previous version. Instead of using contiguous VA range a copy of linear map is now used to perform copying of segments during relocation as it was agreed in the discussion of version 11 of this project. - In addition to using linear map, I also took several ideas from James Morse to better organize the kexec relocation: 1. skip relocation function entirely if that is not needed 2. remove the PoC flushing function since it is not needed anymore with MMU enabled. v11: - Fixed missing KEXEC_CORE dependency for trans_pgd.c - Removed useless "if(rc) return rc" statement (thank you Tyler Hicks) - Another 12 patches were accepted into maintainer's get. Re-based patches against: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git Branch: for-next/kexec v10: - Addressed a lot of comments form James Morse and from Marc Zyngier - Added review-by's - Synchronized with mainline v9: - 9 patches from previous series landed in upstream, so now series is smaller - Added two patches from James Morse to address idmap issues for machines with high physical addresses. - Addressed comments from Selin Dag about compiling issues. He also tested my series and got similar performance results: ~60 ms instead of ~580 ms with an initramfs size of ~120MB. v8: - Synced with mainline to keep series up-to-date v7: -- Addressed comments from James Morse - arm64: hibernate: pass the allocated pgdp to ttbr0 Removed "Fixes" tag, and added Added Reviewed-by: James Morse - arm64: hibernate: check pgd table allocation Sent out as a standalone patch so it can be sent to stable Series applies on mainline + this patch - arm64: hibernate: add trans_pgd public functions Remove second allocation of tmp_pg_dir in swsusp_arch_resume Added Reviewed-by: James Morse <james.morse@xxxxxxx> - arm64: kexec: move relocation function setup and clean up Fixed typo in commit log Changed kern_reloc to phys_addr_t types. Added explanation why kern_reloc is needed. Split into four patches: arm64: kexec: make dtb_mem always enabled arm64: kexec: remove unnecessary debug prints arm64: kexec: call kexec_image_info only once arm64: kexec: move relocation function setup - arm64: kexec: add expandable argument to relocation function Changed types of new arguments from unsigned long to phys_addr_t. Changed offset prefix to KEXEC_* Split into four patches: arm64: kexec: cpu_soft_restart change argument types arm64: kexec: arm64_relocate_new_kernel clean-ups arm64: kexec: arm64_relocate_new_kernel don't use x0 as temp arm64: kexec: add expandable argument to relocation function - arm64: kexec: configure trans_pgd page table for kexec Added invalid entries into EL2 vector table Removed KEXEC_EL2_VECTOR_TABLE_SIZE and KEXEC_EL2_VECTOR_TABLE_OFFSET Copy relocation functions and table into separate pages Changed types in kern_reloc_arg. Split into three patches: arm64: kexec: offset for relocation function arm64: kexec: kexec EL2 vectors arm64: kexec: configure trans_pgd page table for kexec - arm64: kexec: enable MMU during kexec relocation Split into two patches: arm64: kexec: enable MMU during kexec relocation arm64: kexec: remove head from relocation argument v6: - Sync with mainline tip - Added Acked's from Dave Young v5: - Addressed comments from Matthias Brugger: added review-by's, improved comments, and made cleanups to swsusp_arch_resume() in addition to create_safe_exec_page(). - Synced with mainline tip. v4: - Addressed comments from James Morse. - Split "check pgd table allocation" into two patches, and moved to the beginning of series for simpler backport of the fixes. Added "Fixes:" tags to commit logs. - Changed "arm64, hibernate:" to "arm64: hibernate:" - Added Reviewed-by's - Moved "add PUD_SECT_RDONLY" earlier in series to be with other clean-ups - Added "Derived from:" to arch/arm64/mm/trans_pgd.c - Removed "flags" from trans_info - Changed .trans_alloc_page assumption to return zeroed page. - Simplify changes to trans_pgd_map_page(), by keeping the old code. - Simplify changes to trans_pgd_create_copy, by keeping the old code. - Removed: "add trans_pgd_create_empty" - replace init_mm with NULL, and keep using non "__" version of populate functions. v3: - Split changes to create_safe_exec_page() into several patches for easier review as request by Mark Rutland. This is why this series has 3 more patches. - Renamed trans_table to tans_pgd as agreed with Mark. The header comment in trans_pgd.c explains that trans stands for transitional page tables. Meaning they are used in transition between two kernels. v2: - Fixed hibernate bug reported by James Morse - Addressed comments from James Morse: * More incremental changes to trans_table * Removed TRANS_FORCEMAP * Added kexec reboot data for image with 380M in size. Enable MMU during kexec relocation in order to improve reboot performance. If kexec functionality is used for a fast system update, with a minimal downtime, the relocation of kernel + initramfs takes a significant portion of reboot. The reason for slow relocation is because it is done without MMU, and thus not benefiting from D-Cache. Performance data ---------------- Cavium ThunderX2: Kernel Image size: 38M Iniramfs size: 46M Total relocation size: 84M MMU-disabled: relocation 7.489539915s MMU-enabled: relocation 0.03946095s Relocation performance is improved 190 times. Broadcom Stingray: For this experiment, the size of kernel plus initramfs is small, only 25M. If initramfs was larger, than the improvements would be greater, as time spent in relocation is proportional to the size of relocation. MMU-disabled:: kernel shutdown 0.022131328s relocation 0.440510736s kernel startup 0.294706768s Relocation was taking: 58.2% of reboot time MMU-enabled: kernel shutdown 0.032066576s relocation 0.022158152s kernel startup 0.296055880s Now: Relocation takes 6.3% of reboot time Total reboot is x2.16 times faster. With bigger userland (fitImage 380M), the reboot time is improved by 3.57s, and is reduced from 3.9s down to 0.33s Previous approaches and discussions ----------------------------------- v12: https://lore.kernel.org/lkml/20210303002230.1083176-1-pasha.tatashin@xxxxxxxxxx v11: https://lore.kernel.org/lkml/20210127172706.617195-1-pasha.tatashin@xxxxxxxxxx v10: https://lore.kernel.org/linux-arm-kernel/20210125191923.1060122-1-pasha.tatashin@xxxxxxxxxx v9: https://lore.kernel.org/lkml/20200326032420.27220-1-pasha.tatashin@xxxxxxxxxx v8: https://lore.kernel.org/lkml/20191204155938.2279686-1-pasha.tatashin@xxxxxxxxxx v7: https://lore.kernel.org/lkml/20191016200034.1342308-1-pasha.tatashin@xxxxxxxxxx v6: https://lore.kernel.org/lkml/20191004185234.31471-1-pasha.tatashin@xxxxxxxxxx v5: https://lore.kernel.org/lkml/20190923203427.294286-1-pasha.tatashin@xxxxxxxxxx v4: https://lore.kernel.org/lkml/20190909181221.309510-1-pasha.tatashin@xxxxxxxxxx v3: https://lore.kernel.org/lkml/20190821183204.23576-1-pasha.tatashin@xxxxxxxxxx v2: https://lore.kernel.org/lkml/20190817024629.26611-1-pasha.tatashin@xxxxxxxxxx v1: https://lore.kernel.org/lkml/20190801152439.11363-1-pasha.tatashin@xxxxxxxxxx James Morse (4): arm64: hyp-stub: Check the size of the HYP stub's vectors arm64: hyp-stub: Move invalid vector entries into the vectors arm64: hyp-stub: Move el1_sync into the vectors arm64: kexec: Use dcache ops macros instead of open-coding Pavel Tatashin (13): arm64: kernel: add helper for booted at EL2 and not VHE arm64: trans_pgd: hibernate: Add trans_pgd_copy_el2_vectors arm64: hibernate: abstract ttrb0 setup function arm64: kexec: flush image and lists during kexec load time arm64: kexec: skip relocation code for inplace kexec arm64: kexec: pass kimage as the only argument to relocation function arm64: kexec: kexec may require EL2 vectors arm64: kexec: relocate in EL1 mode arm64: kexec: use ld script for relocation function arm64: kexec: install a copy of the linear-map arm64: kexec: keep MMU enabled during kexec relocation arm64: kexec: remove the pre-kexec PoC maintenance arm64: kexec: Remove cpu-reset.h Pingfan Liu (1): arm64/mm: remove useless trans_pgd_map_page() arch/arm64/Kconfig | 2 +- arch/arm64/include/asm/assembler.h | 31 ++++- arch/arm64/include/asm/kexec.h | 12 ++ arch/arm64/include/asm/mmu_context.h | 24 ++++ arch/arm64/include/asm/sections.h | 1 + arch/arm64/include/asm/trans_pgd.h | 8 +- arch/arm64/include/asm/virt.h | 8 ++ arch/arm64/kernel/asm-offsets.c | 11 ++ arch/arm64/kernel/cpu-reset.S | 7 +- arch/arm64/kernel/cpu-reset.h | 32 ----- arch/arm64/kernel/hibernate-asm.S | 20 ---- arch/arm64/kernel/hibernate.c | 56 +++------ arch/arm64/kernel/hyp-stub.S | 95 +++++++-------- arch/arm64/kernel/machine_kexec.c | 168 +++++++++++++++------------ arch/arm64/kernel/relocate_kernel.S | 72 ++++++------ arch/arm64/kernel/sdei.c | 2 +- arch/arm64/kernel/vmlinux.lds.S | 19 +++ arch/arm64/mm/trans_pgd.c | 77 ++++-------- 18 files changed, 315 insertions(+), 330 deletions(-) delete mode 100644 arch/arm64/kernel/cpu-reset.h -- 2.25.1 _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
