From patchwork Wed Sep 11 13:30:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anna-Maria Behnsen X-Patchwork-Id: 13800580 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9185F190052; Wed, 11 Sep 2024 13:30:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726061413; cv=none; b=iv6DuxjhN4KqUncfB8pt/i5C/xjI4X65rcb/cA0n9tl11txbEXFiigExVZMSF3doq4D2k0EJFCz+7ELQm/Ckxh5L1tN8CGG4aRiPcOsv0pBxjq9w8FfypbKDxnJmtovSPf05s9NYNkNYPREZVF3uVzC2fCga5g+w5jfONHH/gmo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726061413; c=relaxed/simple; bh=cF6oOAMfCeoTCaLpR/GZtD9S8qUF3cOcM6UGbdVx5+Y=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=U2PK0FYtgRSgoEdnUd46hB4VWYaB2UgRMKpBvyme+drRrY6kTJt0tNRdOhe91niVeTVR31JfFb45WehWnIieuWYy7sCPcOxY9D/0c7AL3ncvoDKRRR9BPXDyrEXj6dIjV5CM44XV4NW3XOIwo7HsnRqPZujocEDnsZI8Fdey4KQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=sfw1ByL7; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=RrpXnyUy; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="sfw1ByL7"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="RrpXnyUy" From: Anna-Maria Behnsen DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1726061409; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=UDMkmxjITMPgOf2byw/Xt3H3B0E1TY+ptDWM2cYP80U=; b=sfw1ByL7bBp7d0WPlIuC0bO3X8BckkffXruGH3fOqv49Pctr0clIy4Vz669FXT+yd2S+QT U1cexsFbtmfRtYKNbNYo+kXOywPNP26TJauQR63Cl1CS/R2ZTHj0AWdAePF4BD9fDSHcaf 0qfkseWRQDReI48g5M7zVQtkRsJnn7+ko/Wx/0cwKBMgxRjT8MCoLB8kCEaQtWK78u0ZZG SiK/LMe9NuHYLJDr+dQYeDdUZCtHBlYmKBAuIZStho3fbPhw3k/xwlFYVcG94wfULKBnvC sUagte0O0+rsFVJVThSvNZ5nFeACQckp7vGIo5YQyUlEu0/SWqoX55AKmiUWzw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1726061409; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=UDMkmxjITMPgOf2byw/Xt3H3B0E1TY+ptDWM2cYP80U=; b=RrpXnyUyhbcguowfOb2LjHWLvYxDsdqwm7bx5GdxQeYWcUQ1nf8ptDqhp0qdmXo7K/RsLV 3W1CjpokraucYGAw== Date: Wed, 11 Sep 2024 15:30:04 +0200 Subject: [PATCH 20/24] timekeeping: Rework timekeeping_resume() to use shadow_timekeeper Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240911-devel-anna-maria-b4-timers-ptp-timekeeping-v1-20-f7cae09e25d6@linutronix.de> References: <20240911-devel-anna-maria-b4-timers-ptp-timekeeping-v1-0-f7cae09e25d6@linutronix.de> In-Reply-To: <20240911-devel-anna-maria-b4-timers-ptp-timekeeping-v1-0-f7cae09e25d6@linutronix.de> To: John Stultz , Frederic Weisbecker , Thomas Gleixner Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Miroslav Lichvar , Richard Cochran , Christopher S Hall , Anna-Maria Behnsen Updates of the timekeeper can be done by operating on the shadow timekeeper and afterwards copying the result into the real timekeeper. This has the advantage, that the sequence count write protected region is kept as small as possible. While the sequence count held time is not relevant for the resume path as there is no concurrency, there is no reason to have this function different than all the other update sites. Convert timekeeping_inject_offset() to use this scheme and cleanup the variable declaration while at it. Signed-off-by: Anna-Maria Behnsen --- kernel/time/timekeeping.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 244bb58dcda9..d4a0d37f88f5 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -1912,12 +1912,12 @@ void timekeeping_inject_sleeptime64(const struct timespec64 *delta) */ void timekeeping_resume(void) { - struct timekeeper *tk = &tk_core.timekeeper; + struct timekeeper *tk = &tk_core.shadow_timekeeper; struct clocksource *clock = tk->tkr_mono.clock; - unsigned long flags; struct timespec64 ts_new, ts_delta; - u64 cycle_now, nsec; bool inject_sleeptime = false; + u64 cycle_now, nsec; + unsigned long flags; read_persistent_clock64(&ts_new); @@ -1925,7 +1925,6 @@ void timekeeping_resume(void) clocksource_resume(); raw_spin_lock_irqsave(&tk_core.lock, flags); - write_seqcount_begin(&tk_core.seq); /* * After system resumes, we need to calculate the suspended time and @@ -1960,8 +1959,7 @@ void timekeeping_resume(void) tk->ntp_error = 0; timekeeping_suspended = 0; - timekeeping_update(&tk_core, tk, TK_MIRROR | TK_CLOCK_WAS_SET); - write_seqcount_end(&tk_core.seq); + timekeeping_update_staged(&tk_core, TK_CLOCK_WAS_SET); raw_spin_unlock_irqrestore(&tk_core.lock, flags); touch_softlockup_watchdog();