Author: smh Date: Wed Jun 29 07:55:45 2016 New Revision: 302265 URL: https://svnweb.freebsd.org/changeset/base/302265
Log: Allow ZFS ARC min / max to be tuned at runtime Prior to this change ZFS ARC min / max could only be changed using boot time tunables, this allows the values to be tuned at runtime using the sysctls: * vfs.zfs.arc_max * vfs.zfs.arc_min When adjusting ZFS ARC minimum the memory used will only reduce to the new minimum given memory pressure. Reviewed by: allanjude Approved by: re (gjb) MFC after: 2 weeks Relnotes: yes Sponsored by: Multiplay Differential Revision: https://reviews.freebsd.org/D5907 Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_pool.c Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Wed Jun 29 07:00:15 2016 (r302264) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Wed Jun 29 07:55:45 2016 (r302265) @@ -238,10 +238,15 @@ int zfs_disable_dup_eviction = 0; uint64_t zfs_arc_average_blocksize = 8 * 1024; /* 8KB */ u_int zfs_arc_free_target = 0; +/* Absolute min for arc min / max is 16MB. */ +static uint64_t arc_abs_min = 16 << 20; + static int sysctl_vfs_zfs_arc_free_target(SYSCTL_HANDLER_ARGS); static int sysctl_vfs_zfs_arc_meta_limit(SYSCTL_HANDLER_ARGS); +static int sysctl_vfs_zfs_arc_max(SYSCTL_HANDLER_ARGS); +static int sysctl_vfs_zfs_arc_min(SYSCTL_HANDLER_ARGS); -#ifdef _KERNEL +#if defined(__FreeBSD__) && defined(_KERNEL) static void arc_free_target_init(void *unused __unused) { @@ -255,10 +260,10 @@ TUNABLE_QUAD("vfs.zfs.arc_meta_limit", & TUNABLE_QUAD("vfs.zfs.arc_meta_min", &zfs_arc_meta_min); TUNABLE_INT("vfs.zfs.arc_shrink_shift", &zfs_arc_shrink_shift); SYSCTL_DECL(_vfs_zfs); -SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, arc_max, CTLFLAG_RDTUN, &zfs_arc_max, 0, - "Maximum ARC size"); -SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, arc_min, CTLFLAG_RDTUN, &zfs_arc_min, 0, - "Minimum ARC size"); +SYSCTL_PROC(_vfs_zfs, OID_AUTO, arc_max, CTLTYPE_U64 | CTLFLAG_RWTUN, + 0, sizeof(uint64_t), sysctl_vfs_zfs_arc_max, "QU", "Maximum ARC size"); +SYSCTL_PROC(_vfs_zfs, OID_AUTO, arc_min, CTLTYPE_U64 | CTLFLAG_RWTUN, + 0, sizeof(uint64_t), sysctl_vfs_zfs_arc_min, "QU", "Minimum ARC size"); SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, arc_average_blocksize, CTLFLAG_RDTUN, &zfs_arc_average_blocksize, 0, "ARC average blocksize"); @@ -884,7 +889,7 @@ struct arc_buf_hdr { l1arc_buf_hdr_t b_l1hdr; }; -#ifdef _KERNEL +#if defined(__FreeBSD__) && defined(_KERNEL) static int sysctl_vfs_zfs_arc_meta_limit(SYSCTL_HANDLER_ARGS) { @@ -902,6 +907,70 @@ sysctl_vfs_zfs_arc_meta_limit(SYSCTL_HAN arc_meta_limit = val; return (0); } + +static int +sysctl_vfs_zfs_arc_max(SYSCTL_HANDLER_ARGS) +{ + uint64_t val; + int err; + + val = zfs_arc_max; + err = sysctl_handle_64(oidp, &val, 0, req); + if (err != 0 || req->newptr == NULL) + return (err); + + if (val < arc_abs_min || val > kmem_size()) + return (EINVAL); + if (val < arc_c_min) + return (EINVAL); + if (zfs_arc_meta_limit > 0 && val < zfs_arc_meta_limit) + return (EINVAL); + + arc_c_max = val; + + arc_c = arc_c_max; + arc_p = (arc_c >> 1); + + if (zfs_arc_meta_limit == 0) { + /* limit meta-data to 1/4 of the arc capacity */ + arc_meta_limit = arc_c_max / 4; + } + + /* if kmem_flags are set, lets try to use less memory */ + if (kmem_debugging()) + arc_c = arc_c / 2; + + zfs_arc_max = arc_c; + + return (0); +} + +static int +sysctl_vfs_zfs_arc_min(SYSCTL_HANDLER_ARGS) +{ + uint64_t val; + int err; + + val = zfs_arc_min; + err = sysctl_handle_64(oidp, &val, 0, req); + if (err != 0 || req->newptr == NULL) + return (err); + + if (val < arc_abs_min || val > arc_c_max) + return (EINVAL); + + arc_c_min = val; + + if (zfs_arc_meta_min == 0) + arc_meta_min = arc_c_min / 2; + + if (arc_c < arc_c_min) + arc_c = arc_c_min; + + zfs_arc_min = arc_c_min; + + return (0); +} #endif static arc_buf_t *arc_eviction_list; @@ -5385,8 +5454,8 @@ arc_init(void) arc_c = MIN(arc_c, vmem_size(heap_arena, VMEM_ALLOC | VMEM_FREE) / 8); #endif #endif /* illumos */ - /* set min cache to 1/32 of all memory, or 16MB, whichever is more */ - arc_c_min = MAX(arc_c / 4, 16 << 20); + /* set min cache to 1/32 of all memory, or arc_abs_min, whichever is more */ + arc_c_min = MAX(arc_c / 4, arc_abs_min); /* set max to 1/2 of all memory, or all but 1GB, whichever is more */ if (arc_c * 8 >= 1 << 30) arc_c_max = (arc_c * 8) - (1 << 30); @@ -5407,11 +5476,11 @@ arc_init(void) #ifdef _KERNEL /* * Allow the tunables to override our calculations if they are - * reasonable (ie. over 16MB) + * reasonable. */ - if (zfs_arc_max > 16 << 20 && zfs_arc_max < kmem_size()) + if (zfs_arc_max > arc_abs_min && zfs_arc_max < kmem_size()) arc_c_max = zfs_arc_max; - if (zfs_arc_min > 16 << 20 && zfs_arc_min <= arc_c_max) + if (zfs_arc_min > arc_abs_min && zfs_arc_min <= arc_c_max) arc_c_min = zfs_arc_min; #endif Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_pool.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_pool.c Wed Jun 29 07:00:15 2016 (r302264) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_pool.c Wed Jun 29 07:55:45 2016 (r302265) @@ -49,8 +49,8 @@ #include <sys/dsl_userhold.h> #if defined(__FreeBSD__) && defined(_KERNEL) -#include <sys/sysctl.h> #include <sys/types.h> +#include <sys/sysctl.h> #endif /* _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "[email protected]"
