Re: [PATCH] powerpc: Remove dead non-preemption code
From: Shrikanth Hegde <hidden>
Date: 2026-06-19 13:02:01
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Hi Christophe. On 6/19/26 5:38 PM, Christophe Leroy (CS GROUP) wrote:
Since commit 7dadeaa6e851 ("sched: Further restrict the preemption
modes"), powerpc always has CONFIG_PREEMPTION because only
CONFIG_PREEMPT and CONFIG_PREEMPT_LAZY are possible, even in
dynamic preemption mode (see sched_dynamic_mode).
As a consequence, need_irq_preemption() is always true and can be
removed.right. this can be removed now. Thanks for the cleanup.
And because commit bee25f97ad24 ("powerpc: Enable GENERIC_ENTRY
feature") includes linux/irq-entry-common.h which already declares
sk_dynamic_irqentry_exit_cond_resched static key, asm/preempt.h
becauses useless and can be removed.s/becauses/becomes
quoted hunk ↗ jump to hunk
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org> --- arch/powerpc/include/asm/preempt.h | 16 ---------------- arch/powerpc/lib/vmx-helper.c | 2 +- 2 files changed, 1 insertion(+), 17 deletions(-) delete mode 100644 arch/powerpc/include/asm/preempt.hdiff --git a/arch/powerpc/include/asm/preempt.h b/arch/powerpc/include/asm/preempt.h deleted file mode 100644 index 000e2b9681f3..000000000000 --- a/arch/powerpc/include/asm/preempt.h +++ /dev/null@@ -1,16 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef __ASM_POWERPC_PREEMPT_H -#define __ASM_POWERPC_PREEMPT_H - -#include <asm-generic/preempt.h> - -#if defined(CONFIG_PREEMPT_DYNAMIC) -#include <linux/jump_label.h> -DECLARE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched); -#define need_irq_preemption() \ - (static_branch_unlikely(&sk_dynamic_irqentry_exit_cond_resched)) -#else -#define need_irq_preemption() (IS_ENABLED(CONFIG_PREEMPTION)) -#endif - -#endif /* __ASM_POWERPC_PREEMPT_H */diff --git a/arch/powerpc/lib/vmx-helper.c b/arch/powerpc/lib/vmx-helper.c index 57e897b60db8..cc9fb72cb4eb 100644 --- a/arch/powerpc/lib/vmx-helper.c +++ b/arch/powerpc/lib/vmx-helper.c@@ -46,7 +46,7 @@ int exit_vmx_usercopy(void) * set and we are preemptible. The hack here is to schedule a * decrementer to fire here and reschedule for us if necessary. */ - if (need_irq_preemption() && need_resched()) + if (need_resched()) set_dec(1); return 0; }
I booted with the patch, still can change between lazy/full. So, Reviewed-by: Shrikanth Hegde <redacted>