This is a note to let you know that I've just added the patch titled
drm/ttm: Convert -EAGAIN from dmem_cgroup_try_charge to -ENOSPC
to the 7.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-ttm-convert-eagain-from-dmem_cgroup_try_charge-to-enospc.patch
and it can be found in the queue-7.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 591711b32681a04b57d00c2a404658f8419a081c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= <[email protected]>
Date: Fri, 8 May 2026 18:09:20 +0200
Subject: drm/ttm: Convert -EAGAIN from dmem_cgroup_try_charge to -ENOSPC
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From: Thomas Hellström <[email protected]>
commit 591711b32681a04b57d00c2a404658f8419a081c upstream.
dmem_cgroup_try_charge() returns -EAGAIN when the cgroup limit is
hit and the charge fails. TTM has no concept of -EAGAIN from resource
allocation; -ENOSPC is the canonical error meaning "no space, try
eviction". Convert at the source in ttm_resource_alloc() so no caller
needs to handle an unexpected error code, and clean up the now-redundant
-EAGAIN check in ttm_bo_alloc_resource().
Without this, -EAGAIN escaping ttm_resource_alloc() during an eviction
walk causes the walk to terminate early instead of continuing to the
next candidate.
Cc: Friedrich Vock <[email protected]>
Cc: Maarten Lankhorst <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Maxime Ripard <[email protected]>
Cc: Christian Koenig <[email protected]>
Cc: [email protected]
Cc: <[email protected]> # v6.14+
Fixes: 2b624a2c1865 ("drm/ttm: Handle cgroup based eviction in TTM")
Assisted-by: GitHub_Copilot:claude-sonnet-4.6
Signed-off-by: Thomas Hellström <[email protected]>
Reviewed-by: Maarten Lankhorst <[email protected]>
Link:
https://patch.msgid.link/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/gpu/drm/ttm/ttm_bo.c | 2 +-
drivers/gpu/drm/ttm/ttm_resource.c | 5 ++++-
2 files changed, 5 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -740,7 +740,7 @@ static int ttm_bo_alloc_resource(struct
may_evict = (force_space && place->mem_type != TTM_PL_SYSTEM);
ret = ttm_resource_alloc(bo, place, res, force_space ?
&limit_pool : NULL);
if (ret) {
- if (ret != -ENOSPC && ret != -EAGAIN) {
+ if (ret != -ENOSPC) {
dmem_cgroup_pool_state_put(limit_pool);
return ret;
}
--- a/drivers/gpu/drm/ttm/ttm_resource.c
+++ b/drivers/gpu/drm/ttm/ttm_resource.c
@@ -398,8 +398,11 @@ int ttm_resource_alloc(struct ttm_buffer
if (man->cg) {
ret = dmem_cgroup_try_charge(man->cg, bo->base.size, &pool,
ret_limit_pool);
- if (ret)
+ if (ret) {
+ if (ret == -EAGAIN)
+ ret = -ENOSPC;
return ret;
+ }
}
ret = man->func->alloc(man, bo, place, res_ptr);
Patches currently in stable-queue which might be from
[email protected] are
queue-7.0/drm-xe-dma-buf-fix-uaf-with-retry-loop.patch
queue-7.0/drm-ttm-fix-ttm_bo_shrink-infinite-lru-walk-on-backup-failure.patch
queue-7.0/drm-ttm-fix-ttm_bo_swapout-infinite-lru-walk-on-swapout-failure.patch
queue-7.0/drm-gpusvm-fix-unbalanced-unlock-in-drm_gpusvm_scan_.patch
queue-7.0/drm-xe-xelp-fix-wa_18022495364.patch
queue-7.0/drm-xe-dma-buf-handle-empty-bo-and-uaf-races.patch
queue-7.0/drm-ttm-convert-eagain-from-dmem_cgroup_try_charge-to-enospc.patch
