4.19-stable review patch. If anyone has any objections, please let me know.
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From: Dimitri Sivanich sivanich@hpe.com
[ Upstream commit b983b271662bd6104d429b0fd97af3333ba760bf ]
Disabling preemption in the GRU driver is unnecessary, and clashes with sleeping locks in several code paths. Remove preempt_disable and preempt_enable from the GRU driver.
Signed-off-by: Dimitri Sivanich sivanich@hpe.com Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/misc/sgi-gru/grukservices.c | 2 -- drivers/misc/sgi-gru/grumain.c | 4 ---- drivers/misc/sgi-gru/grutlbpurge.c | 2 -- 3 files changed, 8 deletions(-)
diff --git a/drivers/misc/sgi-gru/grukservices.c b/drivers/misc/sgi-gru/grukservices.c index 030769018461b..256be2e12faa1 100644 --- a/drivers/misc/sgi-gru/grukservices.c +++ b/drivers/misc/sgi-gru/grukservices.c @@ -270,7 +270,6 @@ static int gru_get_cpu_resources(int dsr_bytes, void **cb, void **dsr) int lcpu;
BUG_ON(dsr_bytes > GRU_NUM_KERNEL_DSR_BYTES); - preempt_disable(); bs = gru_lock_kernel_context(-1); lcpu = uv_blade_processor_id(); *cb = bs->kernel_cb + lcpu * GRU_HANDLE_STRIDE; @@ -284,7 +283,6 @@ static int gru_get_cpu_resources(int dsr_bytes, void **cb, void **dsr) static void gru_free_cpu_resources(void *cb, void *dsr) { gru_unlock_kernel_context(uv_numa_blade_id()); - preempt_enable(); }
/* diff --git a/drivers/misc/sgi-gru/grumain.c b/drivers/misc/sgi-gru/grumain.c index 8c3e0317c115b..cb4c97210ec36 100644 --- a/drivers/misc/sgi-gru/grumain.c +++ b/drivers/misc/sgi-gru/grumain.c @@ -954,10 +954,8 @@ vm_fault_t gru_fault(struct vm_fault *vmf)
again: mutex_lock(>s->ts_ctxlock); - preempt_disable();
if (gru_check_context_placement(gts)) { - preempt_enable(); mutex_unlock(>s->ts_ctxlock); gru_unload_context(gts, 1); return VM_FAULT_NOPAGE; @@ -966,7 +964,6 @@ vm_fault_t gru_fault(struct vm_fault *vmf) if (!gts->ts_gru) { STAT(load_user_context); if (!gru_assign_gru_context(gts)) { - preempt_enable(); mutex_unlock(>s->ts_ctxlock); set_current_state(TASK_INTERRUPTIBLE); schedule_timeout(GRU_ASSIGN_DELAY); /* true hack ZZZ */ @@ -982,7 +979,6 @@ vm_fault_t gru_fault(struct vm_fault *vmf) vma->vm_page_prot); }
- preempt_enable(); mutex_unlock(>s->ts_ctxlock);
return VM_FAULT_NOPAGE; diff --git a/drivers/misc/sgi-gru/grutlbpurge.c b/drivers/misc/sgi-gru/grutlbpurge.c index be28f05bfafa9..0f837cc3a417b 100644 --- a/drivers/misc/sgi-gru/grutlbpurge.c +++ b/drivers/misc/sgi-gru/grutlbpurge.c @@ -78,7 +78,6 @@ static struct gru_tlb_global_handle *get_lock_tgh_handle(struct gru_state struct gru_tlb_global_handle *tgh; int n;
- preempt_disable(); if (uv_numa_blade_id() == gru->gs_blade_id) n = get_on_blade_tgh(gru); else @@ -92,7 +91,6 @@ static struct gru_tlb_global_handle *get_lock_tgh_handle(struct gru_state static void get_unlock_tgh_handle(struct gru_tlb_global_handle *tgh) { unlock_tgh_handle(tgh); - preempt_enable(); }
/*