6.14-stable review patch. If anyone has any objections, please let me know.
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From: Michal Wajdeczko michal.wajdeczko@intel.com
[ Upstream commit 78d5d1e20d1de9422f013338a0f2311448588ba7 ]
VFs use a relay transaction during the resume/reset flow and use of the GFP_KERNEL flag may conflict with the reclaim:
-> #0 (fs_reclaim){+.+.}-{0:0}: [ ] __lock_acquire+0x1874/0x2bc0 [ ] lock_acquire+0xd2/0x310 [ ] fs_reclaim_acquire+0xc5/0x100 [ ] mempool_alloc_noprof+0x5c/0x1b0 [ ] __relay_get_transaction+0xdc/0xa10 [xe] [ ] relay_send_to+0x251/0xe50 [xe] [ ] xe_guc_relay_send_to_pf+0x79/0x3a0 [xe] [ ] xe_gt_sriov_vf_connect+0x90/0x4d0 [xe] [ ] xe_uc_init_hw+0x157/0x3b0 [xe] [ ] do_gt_restart+0x1ae/0x650 [xe] [ ] xe_gt_resume+0xb6/0x120 [xe] [ ] xe_pm_runtime_resume+0x15b/0x370 [xe] [ ] xe_pci_runtime_resume+0x73/0x90 [xe] [ ] pci_pm_runtime_resume+0xa0/0x100 [ ] __rpm_callback+0x4d/0x170 [ ] rpm_callback+0x64/0x70 [ ] rpm_resume+0x594/0x790 [ ] __pm_runtime_resume+0x4e/0x90 [ ] xe_pm_runtime_get_ioctl+0x9c/0x160 [xe]
Since we have a preallocated pool of relay transactions, which should cover all our normal relay use cases, we may use the GFP_NOWAIT flag when allocating new outgoing transactions.
Signed-off-by: Michal Wajdeczko michal.wajdeczko@intel.com Tested-by: Marcin Bernatowicz marcin.bernatowicz@linux.intel.com Reviewed-by: Marcin Bernatowicz marcin.bernatowicz@linux.intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20250131153713.808-1-michal.wa... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/xe/xe_guc_relay.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/xe/xe_guc_relay.c b/drivers/gpu/drm/xe/xe_guc_relay.c index 8f62de026724c..e5dc94f3e6181 100644 --- a/drivers/gpu/drm/xe/xe_guc_relay.c +++ b/drivers/gpu/drm/xe/xe_guc_relay.c @@ -225,7 +225,7 @@ __relay_get_transaction(struct xe_guc_relay *relay, bool incoming, u32 remote, u * with CTB lock held which is marked as used in the reclaim path. * Btw, that's one of the reason why we use mempool here! */ - txn = mempool_alloc(&relay->pool, incoming ? GFP_ATOMIC : GFP_KERNEL); + txn = mempool_alloc(&relay->pool, incoming ? GFP_ATOMIC : GFP_NOWAIT); if (!txn) return ERR_PTR(-ENOMEM);