linux-kernel - [PATCH 1/2] crypto: pcrypt: Optimize pcrypt_aead_init

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Message-ID: <20250604204742.21183-2-yury.norov@gmail.com>
Date: Wed,  4 Jun 2025 16:47:40 -0400
From: Yury Norov <yury.norov@...il.com>
To: linux-kernel@...r.kernel.org,
	linux-crypto@...r.kernel.org,
	Steffen Klassert <steffen.klassert@...unet.com>,
	Herbert Xu <herbert@...dor.apana.org.au>,
	"David S. Miller" <davem@...emloft.net>,
	Horia Geantă <horia.geanta@....com>,
	Pankaj Gupta <pankaj.gupta@....com>,
	Gaurav Jain <gaurav.jain@....com>
Cc: "Yury Norov [NVIDIA]" <yury.norov@...il.com>
Subject: [PATCH 1/2] crypto: pcrypt: Optimize pcrypt_aead_init_tfm()

From: Yury Norov [NVIDIA] <yury.norov@...il.com>

The function opencodes cpumask_nth(). The dedicated helper is faster
than an open for-loop.

Signed-off-by: Yury Norov [NVIDIA] <yury.norov@...il.com>
---
 crypto/pcrypt.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c
index c33d29a523e0..c3a9d4f2995c 100644
--- a/crypto/pcrypt.c
+++ b/crypto/pcrypt.c
@@ -178,7 +178,7 @@ static int pcrypt_aead_decrypt(struct aead_request *req)
 
 static int pcrypt_aead_init_tfm(struct crypto_aead *tfm)
 {
-	int cpu, cpu_index;
+	int cpu_index;
 	struct aead_instance *inst = aead_alg_instance(tfm);
 	struct pcrypt_instance_ctx *ictx = aead_instance_ctx(inst);
 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(tfm);
@@ -187,10 +187,7 @@ static int pcrypt_aead_init_tfm(struct crypto_aead *tfm)
 	cpu_index = (unsigned int)atomic_inc_return(&ictx->tfm_count) %
 		    cpumask_weight(cpu_online_mask);
 
-	ctx->cb_cpu = cpumask_first(cpu_online_mask);
-	for (cpu = 0; cpu < cpu_index; cpu++)
-		ctx->cb_cpu = cpumask_next(ctx->cb_cpu, cpu_online_mask);
-
+	ctx->cb_cpu = cpumask_nth(cpu_index, cpu_online_mask);
 	cipher = crypto_spawn_aead(&ictx->spawn);
 
 	if (IS_ERR(cipher))
-- 
2.43.0