From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) by lore.proxmox.com (Postfix) with ESMTPS id 7B1A21FF141 for ; Mon, 13 Apr 2026 10:14:50 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 591C91B1D9; Mon, 13 Apr 2026 10:15:38 +0200 (CEST) Message-ID: <9db86c5e-d382-4eed-a1fd-905e44a259e1@proxmox.com> Date: Mon, 13 Apr 2026 10:14:57 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH pve-qemu 0/2] Re-enable tcmalloc as the memory allocator To: "DERUMIER, Alexandre" , "pve-devel@lists.proxmox.com" , "k.chai@proxmox.com" References: <20260410043027.3621673-1-k.chai@proxmox.com> <4628fcc1c283bc4ae80f19e6fe8ae922c0968af9.camel@groupe-cyllene.com> Content-Language: en-US From: Fiona Ebner In-Reply-To: <4628fcc1c283bc4ae80f19e6fe8ae922c0968af9.camel@groupe-cyllene.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1776068029864 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.007 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: WS42NYG3IYYAJ7PR42KVFHIMMEMPMHSS X-Message-ID-Hash: WS42NYG3IYYAJ7PR42KVFHIMMEMPMHSS X-MailFrom: f.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 VE development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Am 10.04.26 um 12:44 PM schrieb DERUMIER, Alexandre: > >>> How does the performance change when doing IO within a QEMU guest? >>> >>> How does this affect the performance for other storage types, like >>> ZFS, >>> qcow2 on top of directory-based storages, qcow2 on top of LVM, LVM- >>> thin, >>> etc. and other workloads like saving VM state during snapshot, >>> transfer >>> during migration, maybe memory hotplug/ballooning, network >>> performance >>> for vNICs? > > Hi Fiona, > > I'm stil running in production (I have keeped tcmalloc after the > removal some year ago from the pve build), and I didn't notice problem. > (but I still don't use pbs). > > But I never have done bench with/without it since 5/6 year. > > Maybe vm memory should be checked too, I'm thinking about RSS memory > with balloon free_page_reporting, to see if it's correcting freeing > memory. Thanks! If it was running fine for you for this long, that is a very good data point :) Still, testing different scenarios/configurations would be nice to rule out that there is a (performance) regression somewhere else.