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Date:      Sun, 2 Nov 2014 19:24:13 +0000
From:      Mark R V Murray <mark@grondar.org>
To:        Konstantin Belousov <kostikbel@gmail.com>
Cc:        "svn-src-head@freebsd.org" <svn-src-head@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>, "src-committers@freebsd.org" <src-committers@freebsd.org>
Subject:   Re: svn commit: r273958 - head/sys/dev/random
Message-ID:  <29A795E1-19E2-49E4-9653-143D3F6F3F12@grondar.org>
In-Reply-To: <20141102192057.GB53947@kib.kiev.ua>
References:  <201411020201.sA221unt091493@svn.freebsd.org> <720EB74E-094A-43F3-8B1C-47BC7F6FECC3@grondar.org> <1414934579.17308.248.camel@revolution.hippie.lan> <6FB65828-6A79-4BDE-A9F7-BC472BA538CE@grondar.org> <CAJ-VmomeOwE3LOpehhJ__G=FCoBDRXrrn%2BSfjwPFODts6YYHNQ@mail.gmail.com> <20141102192057.GB53947@kib.kiev.ua>

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> On 2 Nov 2014, at 19:20, Konstantin Belousov <kostikbel@gmail.com> =
wrote:
>=20
> On Sun, Nov 02, 2014 at 11:05:27AM -0800, Adrian Chadd wrote:
>> [snip all the conversation]
>>=20
>> Ok. There's still a problem that I can trigger by trying to Ctrl-C a
>> process that's blocked reading for randomness. I'll try to chase up
>> more details about and file a PR about it.
>>=20
>> The unfortunate part is that the kernel side stack trace of the
>> offending / hung process isn't currently helpful. :(
>>=20
>=20
>> =46rom what I see, signals are essentially ignored in the read code.
> See random_adaptors.c:random_adaptor_read():
>=20
> 		/* Sleep instead of going into a spin-frenzy */
> 		tsleep(&random_adaptor, PUSER | PCATCH, "block", hz/10);
>=20
> The error which would indicate the signal catch, is dropped.  Also,
> unbound sleep does not drop random_adaptor_lock, which means that
> you cannot module which could provide some more randomness for you,
> while any thread is stuck in read loop.

Hi

I don=E2=80=99t quite follow what you mean, but it sounds like you =
understand
the problem. Could you please explain with a bit more detail?

Thanks,

M
--=20
Mark R V Murray




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