vulkan: Add perf logger mode with concurrency#17944
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0cc4m merged 1 commit intoggml-org:masterfrom Dec 19, 2025
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This implements a variation of the perf logger where rather than timing each operation individually with effectively a barrier in between, we put the timing boundaries where we already synchronize and time the groups of work that normally overlap. This can be useful to help understand whether individual operations need to be optimized, or if the group is already running efficiently. GGML_VK_PERF_LOGGER_CONCURRENT=1 enables the new mode (when GGML_VK_PERF_LOGGER is also set). GGML_VK_SYNC_LOGGER=1 replaces the ENABLE_SYNC_LOGGING compile time switch.
Contributor
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I see surprisingly little difference when using the new concurrency mode: Without: With: Is this expected? |
Contributor
Author
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It depends on the model, some don't have much concurrency. Which model did you try? |
Contributor
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That was just some SmolLM-135M that I had laying around. But I also tried gpt-oss 20B and didn't see that much. I think I just misunderstood what you are doing here. The operations are still timed individually, except if they run concurrently. |
Contributor
Author
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Yeah, it should match the groupings you see if you set GGML_VK_SYNC_LOGGER=1. If an op doesn't run concurrently, then it still gets reported by itself. And fusions still get reported as a single op. |
0cc4m
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Dec 19, 2025
Anico2
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This implements a variation of the perf logger where rather than timing each operation individually with effectively a barrier in between, we put the timing boundaries where we already synchronize and time the groups of work that normally overlap. This can be useful to help understand whether individual operations need to be optimized, or if the group is already running efficiently. GGML_VK_PERF_LOGGER_CONCURRENT=1 enables the new mode (when GGML_VK_PERF_LOGGER is also set). GGML_VK_SYNC_LOGGER=1 replaces the ENABLE_SYNC_LOGGING compile time switch.
blime4
referenced
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in blime4/llama.cpp
Feb 5, 2026
This implements a variation of the perf logger where rather than timing each operation individually with effectively a barrier in between, we put the timing boundaries where we already synchronize and time the groups of work that normally overlap. This can be useful to help understand whether individual operations need to be optimized, or if the group is already running efficiently. GGML_VK_PERF_LOGGER_CONCURRENT=1 enables the new mode (when GGML_VK_PERF_LOGGER is also set). GGML_VK_SYNC_LOGGER=1 replaces the ENABLE_SYNC_LOGGING compile time switch.
Seunghhon
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Apr 26, 2026
This implements a variation of the perf logger where rather than timing each operation individually with effectively a barrier in between, we put the timing boundaries where we already synchronize and time the groups of work that normally overlap. This can be useful to help understand whether individual operations need to be optimized, or if the group is already running efficiently. GGML_VK_PERF_LOGGER_CONCURRENT=1 enables the new mode (when GGML_VK_PERF_LOGGER is also set). GGML_VK_SYNC_LOGGER=1 replaces the ENABLE_SYNC_LOGGING compile time switch.
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This implements a variation of the perf logger where rather than timing each operation individually with effectively a barrier in between, we put the timing boundaries where we already synchronize and time the groups of work that normally overlap. This can be useful to help understand whether individual operations need to be optimized, or if the group is already running efficiently.
GGML_VK_PERF_LOGGER_CONCURRENT=1 enables the new mode (when GGML_VK_PERF_LOGGER is also set).
GGML_VK_SYNC_LOGGER=1 replaces the ENABLE_SYNC_LOGGING compile time switch.