From mboxrd@z Thu Jan 1 00:00:00 1970 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 9137D42070 for ; Tue, 13 Feb 2024 12:36:42 +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=1707827804; cv=none; b=S2K8ERQI6ZNl7Ly9/EI6lRuMJh7IWFrb2WqbDbMza5rzB6tsWcRH0AXGwAxsh9rUXgACUKAnkxriwCD+jr/25xc53ooXRDP/6iynHK2YQkQCIVVnB4eaTqm8mie+sKItMq/8XV3ifkQfsoOy2wdJS8vlU6D4TcbTb4EEobuKlCo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707827804; c=relaxed/simple; bh=u7Gj4MawtZchNvB4IMfRVaTsXDme7kgSGLdFK94qFWw=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=GL6RVRP/g/LC5AQ4ynIi/Ei9OUGWbzSOTM6LhlALGJPlNyAlY5Drm+AoULx+3TYuaJhdw5Js+d/QShR0TRA0gdtoVgfhyGUIFZi1hlytPMVIjTbgkOWl/+MLq4E1gXyNzKUMCZSvmxCsfhk5ABSYhuJDA4N6jkv2VHlmBwC679c= 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=KVO9fvKU; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=wHnozyNz; 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="KVO9fvKU"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="wHnozyNz" From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1707827800; 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: in-reply-to:in-reply-to:references:references; bh=pb2pqQV0xUnwZMXOVMtuXzPc3E6lATgDDAmVYInJbIQ=; b=KVO9fvKU4jfYtiqA6VTtqgUIfPRmafYvV9hD95YC+/7FJIc98F3a6ynNQse9woP+fYYxYq Cn2+7bSlzRn1zeQetpEFXS8IgasjECZe25f60L+ZmIij70bHmjJsh/DEeOQvmngJ05FhKU +Z6Iv7x1PNstbMFvLBxksbn8c1N16yBQT55YpizuJv/oT4eQvzODd3HYWQg5cIb5SiuAYv HCWCKbdSwxT11pq1/o/jj061r0pB7gxF0kXCDUvlb4fQBsuqvnA9lab9Bneq+db64ORDaM j6KEEdT8AA8+HSNGbkcTqiMmEoMzjStdypO2VVYGmCsbNFDp8J1HS5Ci4XxLjw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1707827800; 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: in-reply-to:in-reply-to:references:references; bh=pb2pqQV0xUnwZMXOVMtuXzPc3E6lATgDDAmVYInJbIQ=; b=wHnozyNza0ssaJwmrK8QajDYWvto8xHEeJV9cUBfbUWHNhE/+8gwtoKJcPcbixESCm0MoK PW6n+TVq3hXwQHBw== To: Costa Shulyupin , Waiman Long , linux-kernel@vger.kernel.org Cc: Frederic Weisbecker Subject: Re: [PATCH] hrtimer: select housekeeping CPU during migration In-Reply-To: <20240211135213.2518068-1-costa.shul@redhat.com> References: <20240211135213.2518068-1-costa.shul@redhat.com> Date: Tue, 13 Feb 2024 13:36:40 +0100 Message-ID: <87o7ckh76v.ffs@tglx> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Sun, Feb 11 2024 at 15:52, Costa Shulyupin wrote: > because during CPU deactivation a timer can migrate > to isolated CPU and break CPU isolation. That's not a sentence. > For reference see function get_nohz_timer_target, get_nohz_timer_target() > which selects CPU for new timers from > housekeeping_cpumask(HK_TYPE_TIMER) But what is the point of this statement? > Inspired by Waiman Long Can you please use a proper tag, i.e. Suggested-by and not invent some random free form text just because? > Signed-off-by: Costa Shulyupin > --- > kernel/time/hrtimer.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c > index f82997cf53b6..460d916e24b7 100644 > --- a/kernel/time/hrtimer.c > +++ b/kernel/time/hrtimer.c > @@ -2227,7 +2227,7 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, > int hrtimers_cpu_dying(unsigned int dying_cpu) > { > struct hrtimer_cpu_base *old_base, *new_base; > - int i, ncpu = cpumask_first(cpu_active_mask); > + int i, ncpu = cpumask_any_and(cpu_active_mask, housekeeping(HK_TYPE_TIMER)); > pr_debug("ncpu=%d, dying_cpu=%d\n", ncpu, dying_cpu); > > tick_cancel_sched_timer(dying_cpu); Q: Against which tree is this supposed to apply? A: Against some private tree of yours which added the pr_debug() in a previous commit. Can you please read and follow Documentation/process/ and provide patches which actually can be applied without fixing them up manually? Thanks, tglx