From 367189efae8b53ec2ade37a1c079fd8f69244b9e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Fri, 26 May 2023 17:54:01 +0100 Subject: [PATCH] accel/tcg: include cs_base in our hash calculations MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We weren't using cs_base in the hash calculations before. Since the arm front end moved a chunk of flags in a378206a20 (target/arm: Move mode specific TB flags to tb->cs_base) they comprise of an important part of the execution state. Widen the tb_hash_func to include cs_base and expand to qemu_xxhash8() to accommodate it. My initial benchmark shows very little difference in the runtime. Before: armhf ➜ hyperfine -w 2 -m 20 "./arm-softmmu/qemu-system-arm -cpu cortex-a15 -machine type=virt,highmem=off -display none -m 2048 -serial mon:stdio -netdev user,id=unet,hostfwd=tcp::2222-:22 -device virtio-net-pci,netdev=unet -device virtio-scsi-pci -blockdev driver=raw,node-name=hd,discard=unmap,file.driver=host_device,file.filename=/dev/zen-disk/debian-bullseye-armhf -device scsi-hd,drive=hd -smp 4 -kernel /home/alex/lsrc/linux.git/builds/arm/arch/arm/boot/zImage -append 'console=ttyAMA0 root=/dev/sda2 systemd.unit=benchmark.service' -snapshot" Benchmark 1: ./arm-softmmu/qemu-system-arm -cpu cortex-a15 -machine type=virt,highmem=off -display none -m 2048 -serial mon:stdio -netdev user,id=unet,hostfwd=tcp::2222-:22 -device virtio-net-pci,netdev=unet -device virtio-scsi-pci -blockdev driver=raw,node-name=hd,discard=unmap,file.driver=host_device,file.filename=/dev/zen-disk/debian-bullseye-armhf -device scsi-hd,drive=hd -smp 4 -kernel /home/alex/lsrc/linux.git/builds/arm/arch/arm/boot/zImage -append 'console=ttyAMA0 root=/dev/sda2 systemd.unit=benchmark.service' -snapshot Time (mean ± σ): 24.627 s ± 2.708 s [User: 34.309 s, System: 1.797 s] Range (min … max): 22.345 s … 29.864 s 20 runs arm64 ➜ hyperfine -w 2 -n 20 "./qemu-system-aarch64 -cpu max,pauth-impdef=on -machine type=virt,virtualization=on,gic-version=3 -display none -serial mon:stdio -netdev user,id=unet,hostfwd=tcp::2222-:22,hostfwd=tcp::1234-:1234 -device virtio-net-pci,netdev=unet -device virtio-scsi-pci -blockdev driver=raw,node-name=hd,discard=unmap,file.driver=host_device,file.filename=/dev/zen-disk/debian-bullseye-arm64 -device scsi-hd,drive=hd -smp 4 -kernel ~/lsrc/linux.git/builds/arm64/arch/arm64/boot/Image.gz -append 'console=ttyAMA0 root=/dev/sda2 systemd.unit=benchmark-pigz.service' -snapshot" Benchmark 1: 20 Time (mean ± σ): 62.559 s ± 2.917 s [User: 189.115 s, System: 4.089 s] Range (min … max): 59.997 s … 70.153 s 10 runs After: armhf Benchmark 1: ./arm-softmmu/qemu-system-arm -cpu cortex-a15 -machine type=virt,highmem=off -display none -m 2048 -serial mon:stdio -netdev user,id=unet,hostfwd=tcp::2222-:22 -device virtio-net-pci,netdev=unet -device virtio-scsi-pci -blockdev driver=raw,node-name=hd,discard=unmap,file.driver=host_device,file.filename=/dev/zen-disk/debian-bullseye-armhf -device scsi-hd,drive=hd -smp 4 -kernel /home/alex/lsrc/linux.git/builds/arm/arch/arm/boot/zImage -append 'console=ttyAMA0 root=/dev/sda2 systemd.unit=benchmark.service' -snapshot Time (mean ± σ): 24.223 s ± 2.151 s [User: 34.284 s, System: 1.906 s] Range (min … max): 22.000 s … 28.476 s 20 runs arm64 hyperfine -w 2 -n 20 "./qemu-system-aarch64 -cpu max,pauth-impdef=on -machine type=virt,virtualization=on,gic-version=3 -display none -serial mon:stdio -netdev user,id=unet,hostfwd=tcp::2222-:22,hostfwd=tcp::1234-:1234 -device virtio-net-pci,netdev=unet -device virtio-scsi-pci -blockdev driver=raw,node-name=hd,discard=unmap,file.driver=host_device,file.filename=/dev/zen-disk/debian-bullseye-arm64 -device scsi-hd,drive=hd -smp 4 -kernel ~/lsrc/linux.git/builds/arm64/arch/arm64/boot/Image.gz -append 'console=ttyAMA0 root=/dev/sda2 systemd.unit=benchmark-pigz.service' -snapshot" Benchmark 1: 20 Time (mean ± σ): 62.769 s ± 1.978 s [User: 188.431 s, System: 5.269 s] Range (min … max): 60.285 s … 66.868 s 10 runs Signed-off-by: Alex Bennée Reviewed-by: Richard Henderson Message-id: 20230526165401.574474-12-alex.bennee@linaro.org Message-Id: <20230524133952.3971948-11-alex.bennee@linaro.org> Signed-off-by: Stefan Hajnoczi --- accel/tcg/cpu-exec.c | 2 +- accel/tcg/tb-hash.h | 4 ++-- accel/tcg/tb-maint.c | 4 ++-- include/qemu/xxhash.h | 23 +++++++++++++++++------ util/qsp.c | 2 +- 5 files changed, 23 insertions(+), 12 deletions(-) diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c index 4a1dce98ff..60ca9e229e 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -233,7 +233,7 @@ static TranslationBlock *tb_htable_lookup(CPUState *cpu, target_ulong pc, } desc.page_addr0 = phys_pc; h = tb_hash_func(phys_pc, (cflags & CF_PCREL ? 0 : pc), - flags, cflags); + flags, cs_base, cflags); return qht_lookup_custom(&tb_ctx.htable, &desc, h, tb_lookup_cmp); } diff --git a/accel/tcg/tb-hash.h b/accel/tcg/tb-hash.h index 1d19c69caa..2ba2193731 100644 --- a/accel/tcg/tb-hash.h +++ b/accel/tcg/tb-hash.h @@ -62,9 +62,9 @@ static inline unsigned int tb_jmp_cache_hash_func(target_ulong pc) static inline uint32_t tb_hash_func(tb_page_addr_t phys_pc, target_ulong pc, - uint32_t flags, uint32_t cf_mask) + uint32_t flags, uint64_t flags2, uint32_t cf_mask) { - return qemu_xxhash6(phys_pc, pc, flags, cf_mask); + return qemu_xxhash8(phys_pc, pc, flags2, flags, cf_mask); } #endif diff --git a/accel/tcg/tb-maint.c b/accel/tcg/tb-maint.c index bc1961ea55..892eecda2d 100644 --- a/accel/tcg/tb-maint.c +++ b/accel/tcg/tb-maint.c @@ -887,7 +887,7 @@ static void do_tb_phys_invalidate(TranslationBlock *tb, bool rm_from_page_list) /* remove the TB from the hash list */ phys_pc = tb_page_addr0(tb); h = tb_hash_func(phys_pc, (orig_cflags & CF_PCREL ? 0 : tb->pc), - tb->flags, orig_cflags); + tb->flags, tb->cs_base, orig_cflags); if (!qht_remove(&tb_ctx.htable, tb, h)) { return; } @@ -968,7 +968,7 @@ TranslationBlock *tb_link_page(TranslationBlock *tb, tb_page_addr_t phys_pc, /* add in the hash table */ h = tb_hash_func(phys_pc, (tb->cflags & CF_PCREL ? 0 : tb->pc), - tb->flags, tb->cflags); + tb->flags, tb->cs_base, tb->cflags); qht_insert(&tb_ctx.htable, tb, h, &existing_tb); /* remove TB from the page(s) if we couldn't insert it */ diff --git a/include/qemu/xxhash.h b/include/qemu/xxhash.h index c2dcccadbf..0259bbef18 100644 --- a/include/qemu/xxhash.h +++ b/include/qemu/xxhash.h @@ -48,8 +48,8 @@ * xxhash32, customized for input variables that are not guaranteed to be * contiguous in memory. */ -static inline uint32_t -qemu_xxhash7(uint64_t ab, uint64_t cd, uint32_t e, uint32_t f, uint32_t g) +static inline uint32_t qemu_xxhash8(uint64_t ab, uint64_t cd, uint64_t ef, + uint32_t g, uint32_t h) { uint32_t v1 = QEMU_XXHASH_SEED + PRIME32_1 + PRIME32_2; uint32_t v2 = QEMU_XXHASH_SEED + PRIME32_2; @@ -59,6 +59,8 @@ qemu_xxhash7(uint64_t ab, uint64_t cd, uint32_t e, uint32_t f, uint32_t g) uint32_t b = ab >> 32; uint32_t c = cd; uint32_t d = cd >> 32; + uint32_t e = ef; + uint32_t f = ef >> 32; uint32_t h32; v1 += a * PRIME32_2; @@ -89,6 +91,9 @@ qemu_xxhash7(uint64_t ab, uint64_t cd, uint32_t e, uint32_t f, uint32_t g) h32 += g * PRIME32_3; h32 = rol32(h32, 17) * PRIME32_4; + h32 += h * PRIME32_3; + h32 = rol32(h32, 17) * PRIME32_4; + h32 ^= h32 >> 15; h32 *= PRIME32_2; h32 ^= h32 >> 13; @@ -100,23 +105,29 @@ qemu_xxhash7(uint64_t ab, uint64_t cd, uint32_t e, uint32_t f, uint32_t g) static inline uint32_t qemu_xxhash2(uint64_t ab) { - return qemu_xxhash7(ab, 0, 0, 0, 0); + return qemu_xxhash8(ab, 0, 0, 0, 0); } static inline uint32_t qemu_xxhash4(uint64_t ab, uint64_t cd) { - return qemu_xxhash7(ab, cd, 0, 0, 0); + return qemu_xxhash8(ab, cd, 0, 0, 0); } static inline uint32_t qemu_xxhash5(uint64_t ab, uint64_t cd, uint32_t e) { - return qemu_xxhash7(ab, cd, e, 0, 0); + return qemu_xxhash8(ab, cd, 0, e, 0); } static inline uint32_t qemu_xxhash6(uint64_t ab, uint64_t cd, uint32_t e, uint32_t f) { - return qemu_xxhash7(ab, cd, e, f, 0); + return qemu_xxhash8(ab, cd, 0, e, f); +} + +static inline uint32_t qemu_xxhash7(uint64_t ab, uint64_t cd, uint64_t ef, + uint32_t g) +{ + return qemu_xxhash8(ab, cd, ef, g, 0); } /* diff --git a/util/qsp.c b/util/qsp.c index 8562b14a87..2fe3764906 100644 --- a/util/qsp.c +++ b/util/qsp.c @@ -144,7 +144,7 @@ uint32_t do_qsp_callsite_hash(const QSPCallSite *callsite, uint64_t ab) uint32_t e = callsite->line; uint32_t f = callsite->type; - return qemu_xxhash6(ab, cd, e, f); + return qemu_xxhash8(ab, cd, 0, e, f); } static inline