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Diffstat (limited to 'gitlab/issues_text/target_arm/host_arm/accel_missing/1857')
| -rw-r--r-- | gitlab/issues_text/target_arm/host_arm/accel_missing/1857 | 52 |
1 files changed, 0 insertions, 52 deletions
diff --git a/gitlab/issues_text/target_arm/host_arm/accel_missing/1857 b/gitlab/issues_text/target_arm/host_arm/accel_missing/1857 deleted file mode 100644 index eca6855ca..000000000 --- a/gitlab/issues_text/target_arm/host_arm/accel_missing/1857 +++ /dev/null @@ -1,52 +0,0 @@ -Major qemu-aarch64 performance slowdown since commit 59b6b42cd3 -Description of problem: -I have observed a major performance slowdown between qemu 8.0.0 and 8.1.0: - - -qemu 8.0.0: 0.8s - -qemu 8.1.0: 6.8s - - -After bisecting the commits between 8.0.0 and 8.1.0, the offending commit is 59b6b42cd3: - - -commit 59b6b42cd3446862567637f3a7ab31d69c9bef51 -Author: Richard Henderson <richard.henderson@linaro.org> -Date: Tue Jun 6 10:19:39 2023 +0100 - - target/arm: Enable FEAT_LSE2 for -cpu max - - Reviewed-by: Peter Maydell <peter.maydell@linaro.org> - Signed-off-by: Richard Henderson <richard.henderson@linaro.org> - Message-id: 20230530191438.411344-21-richard.henderson@linaro.org - Signed-off-by: Peter Maydell <peter.maydell@linaro.org> - - -Reverting the commit in latest master fixes the problem: - -qemu 8.0.0: 0.8s - -qemu 8.1.0: 6.8s - -qemu master + revert 59b6b42cd3: 0.8s - -Alternatively, specify `-cpu cortex-a35` to disable LSE2: - -`time ./qemu-aarch64 -cpu cortex-a35`: 0.8s - -`time ./qemu-aarch64`: 6.77s - -The slowdown is also observed when running qemu-aarch64 on aarch64 machine: - -`time ./qemu-aarch64 /usr/bin/node -e 1`: 2.91s - -`time ./qemu-aarch64 -cpu cortex-a35 /usr/bin/node -e 1`: 1.77s - -The slowdown on x86_64 machine is small: 362ms -> 378ms. -Steps to reproduce: -1. Run `time ./qemu-aarch64 node-aarch64 -e 1` (node-aarch64 is NodeJS v16 built for AArch64) -2. Using qemu master, the output says `0.8s` -3. Using qemu master with commit 59b6b42cd3 reverted, the output says `6.77s` -Additional information: - |