Date: Mon, 20 May 2019 19:05:07 +0300 From: Lev Serebryakov <lev@FreeBSD.org> To: freebsd-fs@freebsd.org, freebsd-hackers@FreeBSD.org, Alexander Motin <mav@FreeBSD.org> Subject: Commit r345200 (new ARC reclamation threads) looks suspicious to me - second potential problem Message-ID: <369cb1e9-f36a-a558-6941-23b9b811825a@FreeBSD.org>
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This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --UjA9hsut7pP6HXGyYiI8hkW1DMFekAsUU Content-Type: multipart/mixed; boundary="e5XAhQSTvMSs9v9w4opHL9AcywXVm0rTy"; protected-headers="v1" From: Lev Serebryakov <lev@FreeBSD.org> Reply-To: lev@FreeBSD.org To: freebsd-fs@freebsd.org, freebsd-hackers@FreeBSD.org, Alexander Motin <mav@FreeBSD.org> Message-ID: <369cb1e9-f36a-a558-6941-23b9b811825a@FreeBSD.org> Subject: Commit r345200 (new ARC reclamation threads) looks suspicious to me - second potential problem --e5XAhQSTvMSs9v9w4opHL9AcywXVm0rTy Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable I'm looking at last commit to 'sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c' (r345200) and have another question. Here are such code: 4960 /* 4961 * Kick off asynchronous kmem_reap()'s of all our caches. 4962 */ 4963 arc_kmem_reap_soon(); 4964 =09 4965 /* 4966 * Wait at least arc_kmem_cache_reap_retry_ms between 4967 * arc_kmem_reap_soon() calls. Without this check it is possible to 4968 * end up in a situation where we spend lots of time reapin= g 4969 * caches, while we're near arc_c_min. Waiting here also gives the 4970 * subsequent free memory check a chance of finding that th= e 4971 * asynchronous reap has already freed enough memory, and we don't 4972 * need to call arc_reduce_target_size(). 4973 */ 4974 delay((hz * arc_kmem_cache_reap_retry_ms + 999) / 1000); 4975 =09 But looks like `arc_kmem_reap_soon()` is synchronous on FreeBSD! So, this `delay()` looks very wrong. Am I right? Looks like it should be `#ifdef illumos`. --=20 // Lev Serebryakov --e5XAhQSTvMSs9v9w4opHL9AcywXVm0rTy-- --UjA9hsut7pP6HXGyYiI8hkW1DMFekAsUU Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQKTBAEBCgB9FiEE+W0coLX0MYtnSzMK6rA8WL/cR48FAlzi0DNfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEY5 NkQxQ0EwQjVGNDMxOEI2NzRCMzMwQUVBQjAzQzU4QkZEQzQ3OEYACgkQ6rA8WL/c R4/G2xAAgTzfzeDRycWw5jwlXWAJwExJh4ItBjDoWwe1U+1Yn0tcd+ZbsZX2iH2K R6MJllylJlYF/VHc1Np022vViKrP0bj9vG26QsRjhXZSoGvBYf9exPEp7GMmO81b U6Rm6JyUeuPvc19Kqusrk3FV2CWtu5dUqgp68n5cmujyztZLi1wobRapAHZ+YnrZ SdwnAF28E9LucgNIb4obbe00gkRNlgfXMhMeVi7Q+If/FTJOApoB5dZRdqkv80DF 7wmRhd/423k3ETrkGbRkJNXkWM2jIU13WAbFLbgcDcHZptdePIA2vQ5/CL1W0yV7 1ShZIk3jLgSI/Ue55UpJkf6kgEhZ9v7fOUCNaN5+BhgEut+shVY+Yd7meii7+vsh 6rOVyuXuOoFZFqbkDSLxhLz/zF/zm3Ee9KTIC8WTyuGpHxtFWY6InJFXlZIoiV+A 6gHbYUoKpDOuSwjW+HsGrSEZfZVaH9PeRb7P8UUu6pcrU6UFJFvnX9zqrG/4Hrvi NHCf8rweBnMUuimmeAa6H4kX7sOaK93azqLrk6wuSQYvZ69r8KIcsRKI6Up48rtn pQgT8bJOG5z4Ayk/PYRcltmug/SCGJnf+dtEDgomLb+qsBUdpmP6j4a9Wcxo66pz 4xUmyU2KzqFmx7Gj2oswGTZk1QS+ONj5dhza0gt+gGZU0CFDaWU= =V3Nd -----END PGP SIGNATURE----- --UjA9hsut7pP6HXGyYiI8hkW1DMFekAsUU--
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