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[209.85.219.178]) by smtp.gmail.com with ESMTPSA id i136-20020a816d8e000000b005e8fc1e90e8sm1852016ywc.111.2024.01.10.12.35.09 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 10 Jan 2024 12:35:09 -0800 (PST) Received: by mail-yb1-f178.google.com with SMTP id 3f1490d57ef6-dbd721384c0so3642166276.1; Wed, 10 Jan 2024 12:35:09 -0800 (PST) X-Received: by 2002:a25:6608:0:b0:dbd:b364:69e7 with SMTP id a8-20020a256608000000b00dbdb36469e7mr184797ybc.77.1704918909452; Wed, 10 Jan 2024 12:35:09 -0800 (PST) List-Id: Discussions about the use of FreeBSD-current List-Archive: https://lists.freebsd.org/archives/freebsd-current List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-current@freebsd.org MIME-Version: 1.0 References: <1749331.ETpRK2a2Mi@ravel> <2136329.mxFCRLsXLg@ravel> In-Reply-To: <2136329.mxFCRLsXLg@ravel> From: Tomek CEDRO Date: Wed, 10 Jan 2024 21:34:57 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: noatime on ufs2 To: freebsd-current@freebsd.org Cc: Warner Losh , Olivier Certner Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 4T9KL84WgNz4fly X-Spamd-Bar: ---- X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US] On Wed, Jan 10, 2024 at 6:36=E2=80=AFPM Olivier Certner wrote: > Both the examples above prompt some straight objections on the current us= efulness of "atime". First, unless you've disabled building the locate dat= abase in cron (enabled by default, on a weekly basis), access times on dire= ctories lose most of their usefulness. Second, if using an IDS, I'm afraid= it's just game over. And even if you think you are not, '460.pkg-checksum= ' at least is readily there to much complicate, or even prevent you from, g= etting package usage information this way (it is enabled by default, and on= a daily basis). > > The general point here is that a single access time is inherently fragile= to interferences by multiple applications for multiple reasons. I am reading this interesting discussion and please verify my general understanding: 1. There is a request for change in core OS / FS mechanism of file access time (atime) because of problem with mailing application? 2. Linux change of approach to atime that keeps its value only around last 24h so we should also change it in FreeBSD? 3. "realtime" is the alternative solution to keep atime intact? Why change well known standardized and widely used mechanism that is here for decades? If there is a problem with an application why change core OS/FS with all possible negative consequences and not fix the application? Wouldn't that break POSIX / backward compatiblity? Thanks :-) Tomek -- CeDeROM, SQ7MHZ, http://www.tomek.cedro.info