From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= Subject: [PATCH v2 5/5] static_key: improve deferred inc behavior Date: Sat, 7 Dec 2013 01:40:06 +0100 Message-ID: <1386376806-924-6-git-send-email-rkrcmar@redhat.com> References: <1386376806-924-1-git-send-email-rkrcmar@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mx1.redhat.com ([209.132.183.28]:57331 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758332Ab3LGAl0 (ORCPT ); Fri, 6 Dec 2013 19:41:26 -0500 In-Reply-To: <1386376806-924-1-git-send-email-rkrcmar@redhat.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, linux-arch@vger.kernel.org, rostedt@goodmis.org, pbonzini@redhat.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, arnd@arndb.de, rusty@rustcorp.com.au, =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= We can cancel deferred static_key_slow_dec() instead of increasing =2Eenabled.counter. Timer now won't fire before 'timeout' since the last increase, so this = patch further stabilizes the case of frequent switching. Signed-off-by: Radim Kr=C4=8Dm=C3=A1=C5=99 --- kernel/jump_label.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/jump_label.c b/kernel/jump_label.c index bd7ad31..9b57261 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -79,7 +79,8 @@ void static_key_slow_inc_deferred(struct static_key_d= eferred *key) STATIC_KEY_CHECK_USE(); if (atomic_dec_if_positive(&key->enabled_debt) >=3D 0) return; - static_key_slow_inc(&key->key); + if (!cancel_delayed_work(&key->work)) + static_key_slow_inc(&key->key); } EXPORT_SYMBOL_GPL(static_key_slow_inc_deferred); =20 --=20 1.8.4.2