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Date: Thu, 25 Feb 2010 05:58:21 -0600
Message-ID: <11167f521002250358i46a09fb6j82aaddbd8e0b8334@mail.gmail.com>
From: "Sam Fourman Jr." <sfourman@gmail.com>
To: Nikolay Denev <ndenev@gmail.com>
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Cc: freebsd-fs@freebsd.org, Harald Schmalzbauer <h.schmalzbauer@omnilan.de>
Subject: Re: ZFS write stalls (starving reads) and tuning
	zfs_write_limit_override
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> Hi,
>
> What I posted was not a patch, but just the lines need to be added to dsl=
_pool.c and it should work for either 8 or CURRENT.
> Here is a patch for 8-STABLE that I just generated, can you try that one =
(pasting in the email in case the email eats the attachment
> ):
>
> --- .zfs/snapshot/orig/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl=
_pool.c =A0 =A0 =A0 =A02009-08-24 07:30:23.677549074 +0300
> +++ sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_pool.c =A0 2010-02=
-19 09:17:50.058020997 +0200
> @@ -47,6 +47,11 @@
> =A0uint64_t zfs_write_limit_override =3D 0;
> =A0extern uint64_t zfs_write_limit_min;
>
> +SYSCTL_DECL(_vfs_zfs);
> +TUNABLE_ULONG("vfs.zfs.write_limit_override", &zfs_write_limit_override)=
;
> +SYSCTL_ULONG(_vfs_zfs, OID_AUTO, zfs_write_limit_override, CTLFLAG_RW, &=
zfs_write_limit_override, 0,
> + =A0 =A0"Override maximum TXG size");
> +
> =A0kmutex_t zfs_write_limit_lock;
>
> =A0static pgcnt_t old_physmem =3D 0;
>


what setting have you found to be the best for zfs_write_limit_override ?

Sam Fourman Jr.
Fourman Networks