From: Chris Torek <chris.torek@gmail.com>
To: Neeraj Singh <nksingh85@gmail.com>
Cc: Junio C Hamano <gitster@pobox.com>,
Jeff Hostetler <git@jeffhostetler.com>,
Git List <git@vger.kernel.org>,
"Neeraj K. Singh" <neerajsi@microsoft.com>
Subject: Re: [PATCH] read-cache: make the index write buffer size 128K
Date: Wed, 24 Feb 2021 23:57:36 -0800 [thread overview]
Message-ID: <CAPx1GvcFMzrFFmwMvDLofj73UcEi6T3u_v+usvENkU2yYGLoaQ@mail.gmail.com> (raw)
In-Reply-To: <CANQDOdd+keN3LyC4CHWDZ3JHYurEy_FLyw5GT5UKqg0RcTA+DA@mail.gmail.com>
On Wed, Feb 24, 2021 at 11:36 PM Neeraj Singh <nksingh85@gmail.com> wrote:
> From a quick perusal of freebsd, st_blksize seems to be the system
> PAGE_SIZE by default (4k most of the time, I assume). The Windows
> equivalent of this value is really tuned to what you want to send down
> when bypassing the cache (to avoid partial cluster/stripe writes).
It's page-size for pipes, sockets, etc., but for real files, it's based on
a report from the underlying file system. It's actually 8k on a typical
ancient UFS file system, 64K on UFS2, and 128K on ZFS, on FreeBSD.
> https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_stat.h.html
> doesn't elicit much confidence. The units of st_blksize aren't even
> defined.
Despite POSIX's rather obstreperous definition of st_blksize, the
units are actually just bytes, in practice.
Chris
prev parent reply other threads:[~2021-02-25 7:59 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-18 2:48 [PATCH] read-cache: make the index write buffer size 128K Neeraj K. Singh via GitGitGadget
2021-02-19 19:12 ` Jeff Hostetler
2021-02-20 3:28 ` Junio C Hamano
2021-02-20 7:56 ` Neeraj Singh
2021-02-21 12:51 ` Junio C Hamano
2021-02-24 20:56 ` Neeraj Singh
2021-02-25 5:41 ` Junio C Hamano
2021-02-25 6:58 ` Chris Torek
2021-02-25 7:16 ` Junio C Hamano
2021-02-25 7:36 ` Neeraj Singh
2021-02-25 7:57 ` Chris Torek [this message]
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