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From: Heiko Carstens <hca@linux.ibm.com>
To: Alexander Gordeev <agordeev@linux.ibm.com>,
	Sven Schnelle <svens@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Christian Borntraeger <borntraeger@linux.ibm.com>,
	Harald Freudenberger <freude@linux.ibm.com>,
	Holger Dengler <dengler@linux.ibm.com>,
	Vineeth Vijayan <vneethv@linux.ibm.com>,
	Peter Oberparleiter <oberpar@linux.ibm.com>,
	Janosch Frank <frankja@linux.ibm.com>,
	Claudio Imbrenda <imbrenda@linux.ibm.com>,
	David Hildenbrand <david@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>
Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/4] KVM: s390: Remove cond_resched() calls
Date: Mon, 27 Jul 2026 18:24:28 +0200	[thread overview]
Message-ID: <20260727162430.1599396-3-hca@linux.ibm.com> (raw)
In-Reply-To: <20260727162430.1599396-1-hca@linux.ibm.com>

Since [1] cond_resched() is a no-op on s390. Remove all calls.

[1] commit 7dadeaa6e851 ("sched: Further restrict the preemption modes")

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---
 arch/s390/include/asm/uv.h  | 1 -
 arch/s390/kvm/gaccess.c     | 8 ++------
 arch/s390/kvm/gmap.c        | 4 ----
 arch/s390/kvm/kvm-s390.c    | 1 -
 arch/s390/kvm/pv.c          | 1 -
 arch/s390/kvm/vsie.c        | 1 -
 arch/s390/mm/gmap_helpers.c | 1 -
 7 files changed, 2 insertions(+), 15 deletions(-)

diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
index d919e69662f5..795da130342a 100644
--- a/arch/s390/include/asm/uv.h
+++ b/arch/s390/include/asm/uv.h
@@ -461,7 +461,6 @@ static inline int uv_call_sched(unsigned long r1, unsigned long r2)
 
 	do {
 		cc = __uv_call(r1, r2);
-		cond_resched();
 	} while (cc > 1);
 	return cc;
 }
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index 36102b2727fb..0d389a302a70 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -151,10 +151,8 @@ static void ipte_lock_simple(struct kvm *kvm)
 	ic = &kvm->arch.sca->ipte_control;
 	old = READ_ONCE(*ic);
 	do {
-		if (old.k) {
-			cond_resched();
+		if (old.k)
 			goto retry;
-		}
 		new = old;
 		new.k = 1;
 	} while (!try_cmpxchg(&ic->val, &old.val, new.val));
@@ -189,10 +187,8 @@ static void ipte_lock_siif(struct kvm *kvm)
 	ic = &kvm->arch.sca->ipte_control;
 	old = READ_ONCE(*ic);
 	do {
-		if (old.kg) {
-			cond_resched();
+		if (old.kg)
 			goto retry;
-		}
 		new = old;
 		new.k = 1;
 		new.kh++;
diff --git a/arch/s390/kvm/gmap.c b/arch/s390/kvm/gmap.c
index 8abb4f55b306..3758e4009709 100644
--- a/arch/s390/kvm/gmap.c
+++ b/arch/s390/kvm/gmap.c
@@ -941,7 +941,6 @@ void gmap_split_huge_pages(struct gmap *gmap)
 		scoped_guard(read_lock, &gmap->kvm->mmu_lock)
 			start = _dat_walk_gfn_range(start, asce_end(gmap->asce), gmap->asce,
 						    &ops, DAT_WALK_IGN_HOLES, gmap);
-		cond_resched();
 	} while (start);
 }
 
@@ -963,7 +962,6 @@ static int _gmap_enable_skeys(struct gmap *gmap)
 	do {
 		scoped_guard(write_lock, &gmap->kvm->mmu_lock)
 			start = dat_reset_skeys(gmap->asce, start);
-		cond_resched();
 	} while (start);
 	return 0;
 }
@@ -1019,7 +1017,6 @@ int gmap_pv_destroy_range(struct gmap *gmap, gfn_t start, gfn_t end, bool interr
 						    DAT_WALK_IGN_HOLES, NULL);
 		if (interruptible && fatal_signal_pending(current))
 			return -EINTR;
-		cond_resched();
 	} while (start && start < end);
 	return 0;
 }
@@ -1138,7 +1135,6 @@ void _gmap_set_cmma_all(struct gmap *gmap, bool dirty)
 			gfn = _dat_walk_gfn_range(gfn, asce_end(gmap->asce), gmap->asce, &ops,
 						  DAT_WALK_IGN_HOLES,
 						  &gmap->kvm->arch.cmma_dirty_pages);
-		cond_resched();
 	} while (gfn);
 }
 
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 150b5dd2170e..2ede8f035a38 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1027,7 +1027,6 @@ static int kvm_s390_set_mem_control(struct kvm *kvm, struct kvm_device_attr *att
 		do {
 			scoped_guard(read_lock, &kvm->mmu_lock)
 				start_gfn = dat_reset_cmma(kvm->arch.gmap->asce, start_gfn);
-			cond_resched();
 		} while (start_gfn);
 		ret = 0;
 		break;
diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
index 1beacc841ca8..935fe308a050 100644
--- a/arch/s390/kvm/pv.c
+++ b/arch/s390/kvm/pv.c
@@ -832,7 +832,6 @@ int kvm_s390_pv_unpack(struct kvm *kvm, unsigned long addr, unsigned long size,
 	while (offset < size) {
 		ret = unpack_one(kvm, addr, tweak, offset, rc, rrc);
 		if (ret == -EAGAIN) {
-			cond_resched();
 			if (fatal_signal_pending(current))
 				break;
 			continue;
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index eea24562e7db..6dcd3b110c17 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -1434,7 +1434,6 @@ static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 		}
 		if (sg)
 			sg = gmap_put(sg);
-		cond_resched();
 	}
 	if (sg)
 		sg = gmap_put(sg);
diff --git a/arch/s390/mm/gmap_helpers.c b/arch/s390/mm/gmap_helpers.c
index 4bf7c9012feb..d564cdefb90f 100644
--- a/arch/s390/mm/gmap_helpers.c
+++ b/arch/s390/mm/gmap_helpers.c
@@ -272,7 +272,6 @@ static int __gmap_helper_unshare_zeropages(struct mm_struct *mm)
 		 * truncation. In that case, the shared zeropage would be gone
 		 * and we can simply retry and make progress.
 		 */
-		cond_resched();
 		goto retry;
 	}
 
-- 
2.53.0


  parent reply	other threads:[~2026-07-27 16:47 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-27 16:24 [PATCH 0/4] s390: Remove or replace cond_resched() calls Heiko Carstens
2026-07-27 16:24 ` [PATCH 1/4] s390/crypto: Replace cond_resched() with schedule() Heiko Carstens
2026-07-27 16:24 ` Heiko Carstens [this message]
2026-07-27 16:24 ` [PATCH 3/4] s390: Remove cond_resched() calls Heiko Carstens
2026-07-27 16:24 ` [PATCH 4/4] s390/cio: " Heiko Carstens

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