From: asmadeus@codewreck.org
To: Christian Schoenebeck <linux_oss@crudebyte.com>
Cc: Eric Van Hensbergen <ericvh@gmail.com>,
v9fs-developer@lists.sourceforge.net,
Eric Van Hensbergen <ericvh@kernel.org>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
Jeff Layton <jlayton@kernel.org>
Subject: Re: [PATCH] fs/9p: Add new options to Documentation
Date: Mon, 3 Apr 2023 03:22:52 +0900 [thread overview]
Message-ID: <ZCnH/HRprV13ugHc@codewreck.org> (raw)
In-Reply-To: <5898218.pUKYPoVZaQ@silver>
Christian Schoenebeck wrote on Sun, Apr 02, 2023 at 04:07:51PM +0200:
> > So, mapping of existing (deprecated) legacy modes:
> > - none (obvious) write_policy=writethrough
> > - *readahead -> cache=file cache_validate_open write_policy=writethrough
> > - mmap -> cache=file cache_validate=open write_policy=writeback
>
> Mmm, why is that "file"? To me "file" sounds like any access to files is
> cached, whereas cache=mmap just uses the cache if mmap() was called, not for
> any other file access.
The semantics are slightly different but I don't think anyone would
mind; mmap was introduced as a way of having minimal caching but file
caching + /sys/class/bdi/9p*/max_bytes to 0 should be almost identical
once we've made sure our cache code sends bigger than 4k writes at a
time (I *think* that's still a problem and there was netfs work in the
ways, but you'd have noticed?)
--
Dominique
next prev parent reply other threads:[~2023-04-02 18:23 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-27 3:05 [PATCH] fs/9p: Add new options to Documentation Eric Van Hensbergen
2023-03-27 15:38 ` Christian Schoenebeck
2023-03-28 15:51 ` Eric Van Hensbergen
2023-04-02 14:07 ` Christian Schoenebeck
2023-04-02 18:22 ` asmadeus [this message]
2023-04-02 18:43 ` Eric Van Hensbergen
2023-04-04 18:26 ` Jeff Layton
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