Date: Mon, 20 May 2019 20:14:31 +0300 From: Lev Serebryakov <lev@FreeBSD.org> To: Ian Lepore <ian@freebsd.org>, 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. Message-ID: <a62c5050-e046-646f-9571-15b39b9292aa@FreeBSD.org> In-Reply-To: <174f71126ca39907370a8904c07546b712ad91b9.camel@freebsd.org> References: <55989579-a228-498e-2842-453cad6f315f@FreeBSD.org> <174f71126ca39907370a8904c07546b712ad91b9.camel@freebsd.org>
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This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --tMa0gZRrxl7pCAF587GN3CtCFfW54v7kb Content-Type: multipart/mixed; boundary="n1o4LvrciTjF6iW6sioyfJbmdqP5wRYyf"; protected-headers="v1" From: Lev Serebryakov <lev@FreeBSD.org> Reply-To: lev@FreeBSD.org To: Ian Lepore <ian@freebsd.org>, freebsd-fs@freebsd.org, freebsd-hackers@FreeBSD.org, Alexander Motin <mav@FreeBSD.org> Message-ID: <a62c5050-e046-646f-9571-15b39b9292aa@FreeBSD.org> Subject: Re: Commit r345200 (new ARC reclamation threads) looks suspicious to me. References: <55989579-a228-498e-2842-453cad6f315f@FreeBSD.org> <174f71126ca39907370a8904c07546b712ad91b9.camel@freebsd.org> In-Reply-To: <174f71126ca39907370a8904c07546b712ad91b9.camel@freebsd.org> --n1o4LvrciTjF6iW6sioyfJbmdqP5wRYyf Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 20.05.2019 19:10, Ian Lepore wrote: > The arc_adjust_needed variable is the gating condition associated with > a condition variable and lock. It is only read or changed while > holding a lock, and the acquiring and releasing of that lock provides > the needed memory barriers. In this case, the association with the > condition variable and lock is somewhat obscured by the way the zthread= > timer stuff works. The arc_adjust_cb_check() function is called from > line 193 of contrib/opensolaris/uts/common/fs/zfs/zthr.c, and that's > where you'll find the code that makes it clear this is an idiomatic > condition variable pattern. Oh, I see now. Right. Thank you for explanation. --=20 // Lev Serebryakov --n1o4LvrciTjF6iW6sioyfJbmdqP5wRYyf-- --tMa0gZRrxl7pCAF587GN3CtCFfW54v7kb Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQKTBAEBCgB9FiEE+W0coLX0MYtnSzMK6rA8WL/cR48FAlzi4HdfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEY5 NkQxQ0EwQjVGNDMxOEI2NzRCMzMwQUVBQjAzQzU4QkZEQzQ3OEYACgkQ6rA8WL/c R49AiA//UnGRvpmcwtG8U2Fxl4bv5CsaIKS1KPCtArSrAfIFQzJeDIeZA77NJ2a1 JCE6FdcgtdIYmPJNQ9AIgr5Nd/xArlnX52ATjRLeAYQYAVB+q3skkZ3p4DveXFEZ sNkz0D9KrpirdILa4crzv5AvIDYfKomHifWuYRb2aLUVZ7uSCeVLB1mRYlTxVQhx usyukK8gGqyWmLDOE0fIV3V1lZn9HL1QDndowsaJEk2LrtR6H5mT62cT9bJ0QDqD SNUS1aEpNVZboh4uscrZdUZMPv77kZsH41r4S7yvfVwqYkhQctJ/iBvwFa0UNUW5 h4mrwB6VlEcWxv0AQ1DjNEbYoGsLM7gJRJ2pTftO/i1wStjZt/W8X6SSzyvJaujr J4878PHwl0N+YKBcfe361u7V7oLBy6SAB4I6AMcDBZQyNePJXWxSuagL8pUKlqGp D9VlOeCzuSwRci43OnnWMNA+rvyNfRwFc5iQNv0ick2gqqrun0cErTrE8YVdtAbC NwZAl481F1mPTBtiqGnDbnbr90uO0VxQfo/S8H54KR6i+Ptx9NjfogpKmqfQKlis zpzLm9VSD0uyyGjoE2FgemKZXc2jLjuy+00NUVRoE9J6ItnSkvVLzMINQWjy4ubd ue+IQvnL3Iz3dlU1cblFL6aYqLNfEcKprT6UKIcQmMHOsnYj2mc= =ykE3 -----END PGP SIGNATURE----- --tMa0gZRrxl7pCAF587GN3CtCFfW54v7kb--
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