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From: "Георгий Кириченко" <georgy@tarantool.org>
To: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: tarantool-patches@freelists.org
Subject: [tarantool-patches] Re: [RFC] fiber: Increase default stack size
Date: Fri, 22 Feb 2019 12:24:12 +0300	[thread overview]
Message-ID: <1732287.KUceHh0FeD@home.lan> (raw)
In-Reply-To: <20190222074607.GU7198@uranus>

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On Friday, February 22, 2019 10:46:07 AM MSK Cyrill Gorcunov wrote:
> On Fri, Feb 22, 2019 at 10:38:42AM +0300, Георгий Кириченко wrote:
> > Hi Cyrill!
> 
> Hi!
> 
> > Thanks for the patch, please see some comments bellow.
> > I like your approach but I think we should do it in a different manner: we
> > could poison 64k page of a fiber stack on start and then check the poison
> > mark when fiber finished. If watermark was overwritten by fiber activity
> > we could use madvise in order to decrease RSS usage.
> 
> I somehow fail to see how it is different from the current scheme.
> In the patch we put single 8 16 bytes poison at 64K (well, page
> aligned offset to be precise) and once the fiber scheduled out we
> test it. I suspect the difference you mean is to _when_ test the poison?
> Or you mean to poison the whole 64K?
I complain only that you check poison on each fiber schedule what could be too 
expensive - a fiber could be scheduled about million times per second.
I think If we would check a fiber stack poison when it goes to recycle so is 
will be a better option.
> 
> p.s.
> You know, I think this stack limits *must not* be fixed in size but
> rather configurable from some parameters (getenv or something). Otherwise
> it will be an endless run and catch game.


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  reply	other threads:[~2019-02-22  9:21 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-21 21:26 Cyrill Gorcunov
2019-02-22  7:38 ` [tarantool-patches] " Георгий Кириченко
2019-02-22  7:46   ` Cyrill Gorcunov
2019-02-22  9:24     ` Георгий Кириченко [this message]
2019-02-22  9:45       ` Cyrill Gorcunov
2019-02-22 10:48 ` [tarantool-patches] " Alexander Turenko
2019-02-22 10:57   ` Cyrill Gorcunov

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