Claude review: drm/ttm: Fix GPU MM stats during pool shrinking

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Overall Series Review

Subject: drm/ttm: Fix GPU MM stats during pool shrinking
Author: Matthew Brost <matthew.brost@intel.com>
Patches: 3
Reviewed: 2026-05-05T08:58:24.455662

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This is a single patch (v2) fixing a real bug in TTM's GPU memory accounting. When TTM pool backup/purge/restore frees pages via `__free_pages()` or `put_page()` directly, it bypasses the `NR_GPU_ACTIVE` / `NR_GPU_RECLAIM` stat updates that were established in commit ae80122f3896. This causes the GPU MM statistics reported via `/proc/meminfo` (or equivalent) to drift out of sync over time as pages are shrunk/backed up.

The fix is clean and well-scoped: a small helper function is introduced and applied to both the existing inline code in `ttm_pool_free_page()` (refactor) and the three buggy call sites. The approach is correct — all three fixed sites free pages that are in `NR_GPU_ACTIVE` state, and `reclaim=false` is the right choice for each.

**Verdict: Looks good.** One minor observation below, but nothing blocking.

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