Date: Wed, 20 Sep 2017 08:36:31 +0000 (UTC) From: Andriy Gapon <avg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r323797 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs Message-ID: <201709200836.v8K8aVoT036210@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: avg Date: Wed Sep 20 08:36:31 2017 New Revision: 323797 URL: https://svnweb.freebsd.org/changeset/base/323797 Log: add vfs_zfs.abd_chunk_size tunable It is reported that the default value of 4KB results in a substantial memory use overhead (at least, on some configurations). Using 1KB seems to reduce the overhead significantly. PR: 222377 Reported by: Sean Chittenden <sean@chittenden.org> MFC after: 1 week Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/abd.c Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/abd.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/abd.c Wed Sep 20 08:27:21 2017 (r323796) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/abd.c Wed Sep 20 08:36:31 2017 (r323797) @@ -150,6 +150,13 @@ boolean_t zfs_abd_scatter_enabled = B_TRUE; */ size_t zfs_abd_chunk_size = 4096; +#if defined(__FreeBSD__) && defined(_KERNEL) +SYSCTL_DECL(_vfs_zfs); + +SYSCTL_ULONG(_vfs_zfs, OID_AUTO, abd_chunk_size, CTLFLAG_RDTUN, + &zfs_abd_chunk_size, 0, "The size of the chunks ABD allocates"); +#endif + #ifdef _KERNEL extern vmem_t *zio_alloc_arena; #endif
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201709200836.v8K8aVoT036210>