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Date: Wed, 5 Jun 2019 15:08:56 +0300
From: Lev Serebryakov <lev@FreeBSD.org>
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Organization: FreeBSD
Message-ID: <1644469784.20190605150856@serebryakov.spb.ru>
To: Slawa Olhovchenkov <slw@zxy.spb.ru>, Ian Lepore <ian@freebsd.org>
CC: freebsd-fs@freebsd.org, freebsd-hackers@FreeBSD.org, 
 Alexander Motin <mav@FreeBSD.org>
Subject: Re: Commit r345200 (new ARC reclamation threads) looks suspicious to
 me.
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Hello Slawa,

Friday, May 31, 2019, 6:12:02 PM, you wrote:

> What about arc_no_grow, for example?
> arc_no_grow set in arc_reap_cb_check(), called from arc_reap_zthr
> thread and in arc_lowmem().
> arc_no_grow test in arc_adapt(), called from
> arc_read()/arc_get_data_impl() called from many unsynced thread.

> How synced visibility of this varibale?
 I don;t like this one either. It is set under mutex (t->zthr_lock of reap
thread/timer), but looks like tit is read by many other threads... And
`arc_lowmem()` uses `arc_adjust_lock`...


-- 
Best regards,
 Lev                            mailto:lev@FreeBSD.org