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however, the result drops to 21595.98 MB/s when percpu_pagelist_high_fraction is set to 0 (enabling PCP high = auto-tuning). I first inspected the auto-tuning code, but the root cause of the = performance degradation lies in the triggering threshold of the free_high heuristic: pcp->free_count >=3D (batch + pcp->high_min / 2) I noticed that commit c544a95 increases this threshold, but = pcp->high_min is relatively small when auto-tuning is enabled, and the PCP draining leads = to the performance degradation. The problem was fixed when increasing the threshold to (batch + = pcp->high / 2). Is it intended to use high_min instead of high in the threshold? Would = it be more adaptive to introduce some new tunables for the free_high = threshold? Best, Shi, Jiacheng=