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
next prev 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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