From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794681971; b=q88xPHVu4QVTogIU5/Dt5QTvn1DvpmdP5MrK9jZ2gvF0f69cJYvOAN8witVe8fbI9bfm 2nUYBZtMvsf+PygOT7DhY062HXmjGMgh0mh3A4SK0ukcJrF0bsD8e9nwqRjIqu1/NiJSp 10zLLqHivqndfdtzhsSr9ctoP2P7t5tFwL6+szYeI0zRmshFiSn1Vs5DK+h7R63gZZS0x 35h4ej+/0wnJNeRvKQNZZxPJl5O9JQilxcM8MZ0O95C3dU/PCGgY+lefuX9JxvHhfJnBB mQJYinQSlsPI7JNs1+damkHhLa3ZYCU1CjQTFrKVbFXnGFEYn/25MY7xzofTMmY1qhw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794681971; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=NZairbP0b4YAQlRihucfuuFbYADO0pre/pVKDVxPxbk=; b=f7UzC/kI3rdJx0TBmj/Hpj6Zf7vhCLWYmGgRG+BxpYkGnbKMTGQWcGzz7oJX8wDa32WW 20j7YQ68OW5dbcDecD+1krN7zjbYv62COLXGsZUXEDzlGXXitTSaShjYjdLX94p2uBOtL oUrBujxFZaCTfxCW0CoqWcVikAMRzCJAoK3N5AujO1IDT5wWWPI/WaAKQNuhx3UOJPxXP MwO4lkibGUbbBsdNI4MMg7S7JZxGPQkfdSaumIqzhvCKszkLK+3kRQBBNnQ/W5CZla3ye sBPSY4RBzFYk5QmpxXAHMfhXLZUL9LGAwU5C2P0c5PjJSjT3q8Zzq/PH1JrqlvxFmMA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=XrLM7YPO; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 54EA1606A330 for ; Sat, 14 Nov 2026 18:46:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=XrLM7YPO Received: by smtp.kernel.org (Postfix) with ESMTPSA id 554021F000C4; Sat, 14 Nov 2026 18:46:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794681970; bh=NZairbP0b4YAQlRihucfuuFbYADO0pre/pVKDVxPxbk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=XrLM7YPOGUJBGY3Sx/TB4LjOdoBG2UXSzX42B8xNPqx3xhlDCKF5GCp1MJwL+C/fS sXAmyE+oJK8ts2hxEIC5wSN6FV2+vGdTVTV/cPUyiij/aS7bDQCJhqKL44fdiTUhxg raMav37302AI6x0yLWZowjdu+t1EpKVZwMSCnAJwjhBmwhq7BvzNVU4pv/wdIWStah pmkV+j1g+9WIbrclAOZ2kYNO/JstfXlyJvZM0YZ6Hy9xNuhyH06xykNpQZPQj2d1KL pISKAWJ3Vbqe3yk2FKoKBjFMJc0XKcNrxndjZylpKFWJ7Mo2GdswSTxVfPx73h6bPI I4oNIP2gB3Ozg== From: Sasha Levin To: stable@vger.kernel.org Cc: "Paul E. McKenney" , Kent Overstreet , Sasha Levin Subject: [PATCH 6.6.y 1/2] srcu: Add NUM_ACTIVE_SRCU_POLL_OLDSTATE Date: Sat, 14 Nov 2026 13:46:08 -0500 Message-ID: <20261114184544.402778-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261109201443-failed-6.6-d06917d0ba22@kernel.org> References: <20261109201443-failed-6.6-d06917d0ba22@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Paul E. McKenney" [ Upstream commit 395e73bd8d35fa9b8505e44f63a2a10abde09cce ] This commit adds NUM_ACTIVE_SRCU_POLL_OLDSTATE, which gives the maximum number of distinct return values from get_state_synchronize_rcu() that can, at a given point in time, correspond to not-completed SRCU grace periods. Reported-by: Kent Overstreet Closes: https://lore.kernel.org/all/irycqy4sinjdgm2hkyix2bffunpcmuwgeufsx6nlljvqme3wiu@ify3zdnrmzph/ Signed-off-by: Paul E. McKenney Stable-dep-of: d06917d0ba22 ("srcu: Add list_splice_init_srcu()") Signed-off-by: Sasha Levin --- include/linux/srcu.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/include/linux/srcu.h b/include/linux/srcu.h index 236610e4a8fa5..f664cba7a80c2 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -61,6 +61,10 @@ unsigned long get_state_synchronize_srcu(struct srcu_struct *ssp); unsigned long start_poll_synchronize_srcu(struct srcu_struct *ssp); bool poll_state_synchronize_srcu(struct srcu_struct *ssp, unsigned long cookie); +// Maximum number of unsigned long values corresponding to +// not-yet-completed SRCU grace periods. +#define NUM_ACTIVE_SRCU_POLL_OLDSTATE 2 + #ifdef CONFIG_NEED_SRCU_NMI_SAFE int __srcu_read_lock_nmisafe(struct srcu_struct *ssp) __acquires(ssp); void __srcu_read_unlock_nmisafe(struct srcu_struct *ssp, int idx) __releases(ssp); -- 2.53.0