From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=13.77.154.182 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793335088; b=tEUVbLvQqYHesDFpgwijGZsGOI5/Mc6bKVXs1TrXKATF+h7VcymRCWiEb1HhQM3IPSnF LDOXbgyC1+2fDoUVkS+HnceHTPFf3D/ovu7wzJQafCbS/oeKWwNOSXd6ZZejLRpo+jaks xXK6s0KIKzAkVJcndBAHu5ympcbJ/O3q3/BOPA7AoOekowEAm+yGb5PxZ0/ZpLdwJYxaU xz6eYDRV1YDguQqevJa2YUhg8i2Jyy4wbz3N4m2TTO+1K+JD0WTdb3UbB76zLMl2pwxRv qj8gHmyw32b6FBtXQ3idral9Do4MmdUt7NdYOBQv370OKOVrqixv2tmKgYkBQhsM9xg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793335088; h=DMARC-Filter:Received:DKIM-Filter:DKIM-Signature:Date:From:To:Cc: Subject:Message-ID:References:MIME-Version:Content-Type: Content-Disposition:In-Reply-To:X-Spam-Status:X-Spam-Checker-Version; bh=WwvcOsEObJ8qzzuuobsmrvvwKxGTjF3cc2+TTpbW1e0=; b=xXia2cN3vuYKVkgWNl64MDPty6ldAebpE5dQSF2F6CLB6GKdqLjx5Nk0rFmmpQcfuKAS VSo28wBbHDA0uIFsWWwYXcO0z1X36ASkMnEqpav9mN41Kr43zpRAZzT+/1B5ss2y3QA+H AmTL2xGVq9yQ7zD1q5GpoeXYGB0rkVXEZqipRVZWawhFtBYNj/DDpOWTKELQRSyJnmfXA UoPvbQImCmxkgAtaS84s21KB6EeUd6ZUG8z6ngQGbBPzshIuUbwXxW1P70Gj56O32+4Ys jh755UUmjK75F5UUix8OkGUXj6BTCh4E09IJnzXvkSe5+E5sFE0YPaqzYY0Rawe34zg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass header.d=linux.microsoft.com header.i=@linux.microsoft.com header.a=rsa-sha256 header.s=default header.b=NJPsdvAy; arc=none smtp.remote-ip=13.77.154.182 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B74A0606A31C; Fri, 30 Oct 2026 04:38:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org B74A0606A31C Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.a=rsa-sha256 header.s=default header.b=NJPsdvAy Received: from kali (unknown [4.213.232.17]) by linux.microsoft.com (Postfix) with ESMTPSA id B148C20B7166; Thu, 29 Oct 2026 21:37:48 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com B148C20B7166 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1793335074; bh=WwvcOsEObJ8qzzuuobsmrvvwKxGTjF3cc2+TTpbW1e0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NJPsdvAyMdl07uIfgdrypurLmehiQZeL4zrhUYZxR96TMW5UhWVD/k6TDPncHWr08 HBDhGEi+B7G362mYoL0sIW0o2+nYfbIXv9oTWCTovARis9B9tYry7LlUyDoTTX9uPX WKbEfCrsL3+VJgHmXIOzVAcYs4vOqZdpgIkHgEhs= Date: Thu, 29 Oct 2026 23:37:54 -0500 From: Sahil Chandna To: Ankur Arora Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, bpf@vger.kernel.org, arnd@arndb.de, catalin.marinas@arm.com, will@kernel.org, peterz@infradead.org, akpm@linux-foundation.org, mark.rutland@arm.com, harisokn@amazon.com, cl@gentwo.org, ast@kernel.org, rafael@kernel.org, daniel.lezcano@kernel.org, memxor@gmail.com, zhenglifeng1@huawei.com, xueshuai@linux.alibaba.com, rdunlap@infradead.org, david.laight.linux@gmail.com, broonie@kernel.org, boris.ostrovsky@oracle.com, ashok.bhat@arm.com Subject: Re: [PATCH v16 00/16] barrier: Add smp_cond_load_{relaxed,acquire}_timeout() Message-ID: References: <20261016070837.440748-1-ankur.a.arora@oracle.com> <87v76lezeq.fsf@oracle.com> X-Mailing-List: bpf@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87v76lezeq.fsf@oracle.com> On Thu, Oct 29, 2026 at 12:31:09AM -0700, Ankur Arora wrote: > > Sahil Chandna writes: > > > On Fri, Oct 16, 2026 at 12:08:21AM -0700, Ankur Arora wrote: > >> Hi, > >> > >> Changes in this version address sashiko comments [17]. The major change > >> is the change in the exit path in __smp_cond_load_relaxed_timeout() > >> which allows us to simplify providing ACQUIRE semantics in > >> smp_cond_load_acquire_timeout(): > >> > [ ... ] > >> > > Hi Ankur, > > > > I tested this patch series on an Azure Cobalt 100 > > (neoverse-n2 on 64-vCPU Hyper-V guest (Standard_D64ps_v6), > > on v7.2.12 + this series + arm64 cpuidle-haltpoll enablement[1] > > > > cpuidle-haltpoll loaded with force=1, guest_halt_poll_ns=200000. > > > > Baseline: no cpuidle driver(only WFI). > > > > Workload: PostgreSQL 16.15/pgbench scale 100, client and server in > > the same VM over a unix socket, with single run: > > > > with (-S) TPC-B-like r/w > > clients base TPS haltpoll lat avg base TPS haltpoll lat avg > > 2 38658 +89% 52->27us 5299 +86% 378->203us > > 4 72987 +99% 55->28 10305 +87% 388->208 > > 16 300895 +91% 53->28 42035 +83% 381->208 > > 32 590987 +93% 55->28 78319 +85% 410->221 > > 64 987749 +0% 65->65 130675 +3% 490->474 > > > > Tested-by: Sahil Chandna > > Thanks Sahil. That's very helpful. Btw what's the (-S) option with > in your first heading? > Hi Ankur, This is the -Select Only option running one statement per transaction, more info captured in [1] [2]. TPC_B like runs small bank transfer transaction. > Just to double check: was the VM created with any special option > such as kvm-arm.wfe_trap_policy? > No, the host in my case is Hyper-V. The cmdline does not have any idle related parameters. console=tty1 console=ttyAMA0 earlycon=pl011,0xeffec000 panic=-1 > -- > ankur > Regards, Sahil [1] https://www.postgresql.org/docs/16/pgbench.html#PGBENCH-OPTION-SELECT-ONLY [2] https://www.postgresql.org/docs/16/pgbench.html#TRANSACTIONS-AND-SCRIPTS