From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [IPv6:2a01:7e0:0:424::9]) by lore.proxmox.com (Postfix) with ESMTPS id 3FC4F1FF13F for ; Thu, 12 Feb 2026 11:19:06 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 2F1F7BCE1; Thu, 12 Feb 2026 11:19:52 +0100 (CET) Message-ID: <06754da1-dc92-4af4-92f6-683240783003@proxmox.com> Date: Thu, 12 Feb 2026 11:19:16 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 2/6] s3-client: add persistent shared request counters for client To: Robert Obkircher , pbs-devel@lists.proxmox.com References: <20260209091533.156902-1-c.ebner@proxmox.com> <20260209091533.156902-3-c.ebner@proxmox.com> <2a88c886-9146-4448-9c5a-d27097f48eeb@proxmox.com> <441d3c9b-8987-46c1-8da9-e9cde4429aab@proxmox.com> <076ebe87-db27-47a0-b3fc-893254fac0db@proxmox.com> Content-Language: en-US, de-DE From: Christian Ebner In-Reply-To: <076ebe87-db27-47a0-b3fc-893254fac0db@proxmox.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1770891470547 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.047 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment RCVD_IN_VALIDITY_CERTIFIED_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. RCVD_IN_VALIDITY_RPBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. RCVD_IN_VALIDITY_SAFE_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Message-ID-Hash: NTVFJHQYNLJTDMCXJQNQJAWRP27DA5ZG X-Message-ID-Hash: NTVFJHQYNLJTDMCXJQNQJAWRP27DA5ZG X-MailFrom: c.ebner@proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox Backup Server development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On 2/12/26 10:54 AM, Robert Obkircher wrote: > > On 2/11/26 13:40, Christian Ebner wrote: >> >> Can you elaborate a bit on this? Not sure if I understand what the >> benefits for this would be. > If those 5 variables share the same cache line then only one core can > write to any of them at a time because they all share a single lock > that bounces back and forth. I don't think it makes a measurable > difference for counting requests though. Thanks a lot for the input! Already looked a bit into it yesterday after you sparked my interest: Might indeed make sense to pad the items to 64-bytes so they are in different cache lines. So I will therefore create a wrapper type for the AtomicU64 counters and align them using the alignment modifier [0]. Also, not sure anymore if `Ordering::SeqCst` is required, this could probably be relaxed to `Ordering::AcqRel` for given use-case. [0] https://doc.rust-lang.org/reference/type-layout.html#the-alignment-modifiers