From 6414b7c981378a6eef480f6806d7cbfc98ca22a1 Mon Sep 17 00:00:00 2001 From: David Strauss Date: Mon, 11 Nov 2013 19:03:31 +1000 Subject: cgroups: Cache controller masks and optimize queues. --- src/core/cgroup.c | 94 ++++++++++++++++++++++++++++++++++++++----------------- src/core/cgroup.h | 2 ++ src/core/unit.c | 8 +++-- src/core/unit.h | 1 + 4 files changed, 75 insertions(+), 30 deletions(-) (limited to 'src/core') diff --git a/src/core/cgroup.c b/src/core/cgroup.c index 1a8fd3728f..c2b1b7d38d 100644 --- a/src/core/cgroup.c +++ b/src/core/cgroup.c @@ -346,21 +346,8 @@ static CGroupControllerMask unit_get_cgroup_mask(Unit *u) { } static CGroupControllerMask unit_get_members_mask(Unit *u) { - CGroupControllerMask mask = 0; - Unit *m; - Iterator i; - assert(u); - - SET_FOREACH(m, u->dependencies[UNIT_BEFORE], i) { - - if (UNIT_DEREF(m->slice) != u) - continue; - - mask |= unit_get_cgroup_mask(m) | unit_get_members_mask(m); - } - - return mask; + return u->cgroup_members_mask; } static CGroupControllerMask unit_get_siblings_mask(Unit *u) { @@ -375,6 +362,26 @@ static CGroupControllerMask unit_get_siblings_mask(Unit *u) { (CGROUP_CPU|CGROUP_BLKIO|CGROUP_CPUACCT); } +static CGroupControllerMask unit_get_target_mask(Unit *u) { + CGroupControllerMask mask; + + mask = unit_get_cgroup_mask(u) | unit_get_members_mask(u) | unit_get_siblings_mask(u); + mask &= u->manager->cgroup_supported; + + return mask; +} + +/* Recurse from a unit up through its containing slices, propagating + * mask bits upward. A unit is also member of itself. */ +void unit_update_member_masks(Unit *u) { + u->cgroup_members_mask |= unit_get_cgroup_mask(u); + if (UNIT_ISSET(u->slice)) { + Unit *s = UNIT_DEREF(u->slice); + s->cgroup_members_mask |= u->cgroup_members_mask; + unit_update_member_masks(s); + } +} + static int unit_create_cgroups(Unit *u, CGroupControllerMask mask) { _cleanup_free_ char *path; int r; @@ -422,8 +429,19 @@ static int unit_create_cgroups(Unit *u, CGroupControllerMask mask) { return 0; } +static bool unit_has_mask_realized(Unit *u, CGroupControllerMask mask) { + return u->cgroup_realized && u->cgroup_mask == mask; +} + +/* Check if necessary controllers and attributes for a unit are in place. + * + * If so, do nothing. + * If not, create paths, move processes over, and set attributes. + * + * Returns 0 on success and < 0 on failure. */ static int unit_realize_cgroup_now(Unit *u) { CGroupControllerMask mask; + int r; assert(u); @@ -432,19 +450,28 @@ static int unit_realize_cgroup_now(Unit *u) { u->in_cgroup_queue = false; } - mask = unit_get_cgroup_mask(u) | unit_get_members_mask(u) | unit_get_siblings_mask(u); - mask &= u->manager->cgroup_supported; + mask = unit_get_target_mask(u); - if (u->cgroup_realized && - u->cgroup_mask == mask) + /* TODO: Consider skipping this check. It may be redundant. */ + if (unit_has_mask_realized(u, mask)) return 0; /* First, realize parents */ - if (UNIT_ISSET(u->slice)) - unit_realize_cgroup_now(UNIT_DEREF(u->slice)); + if (UNIT_ISSET(u->slice)) { + r = unit_realize_cgroup_now(UNIT_DEREF(u->slice)); + if (r < 0) + return r; + } /* And then do the real work */ - return unit_create_cgroups(u, mask); + r = unit_create_cgroups(u, mask); + if (r < 0) + return r; + + /* Finally, apply the necessary attributes. */ + cgroup_context_apply(unit_get_cgroup_context(u), mask, u->cgroup_path); + + return 0; } static void unit_add_to_cgroup_queue(Unit *u) { @@ -459,12 +486,14 @@ static void unit_add_to_cgroup_queue(Unit *u) { unsigned manager_dispatch_cgroup_queue(Manager *m) { Unit *i; unsigned n = 0; + int r; while ((i = m->cgroup_queue)) { assert(i->in_cgroup_queue); - if (unit_realize_cgroup_now(i) >= 0) - cgroup_context_apply(unit_get_cgroup_context(i), i->cgroup_mask, i->cgroup_path); + r = unit_realize_cgroup_now(i); + if (r < 0) + log_warning("Failed to realize cgroups for queued unit %s: %s", i->id, strerror(-r)); n++; } @@ -487,9 +516,22 @@ static void unit_queue_siblings(Unit *u) { if (m == u) continue; + /* Skip units that have a dependency on the slice + * but aren't actually in it. */ if (UNIT_DEREF(m->slice) != slice) continue; + /* No point in doing cgroup application for units + * without active processes. */ + if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(m))) + continue; + + /* If the unit doesn't need any new controllers + * and has current ones realized, it doesn't need + * any changes. */ + if (unit_has_mask_realized(m, unit_get_target_mask(m))) + continue; + unit_add_to_cgroup_queue(m); } @@ -521,13 +563,9 @@ int unit_realize_cgroup(Unit *u) { /* Add all sibling slices to the cgroup queue. */ unit_queue_siblings(u); - /* And realize this one now */ + /* And realize this one now (and apply the values) */ r = unit_realize_cgroup_now(u); - /* And apply the values */ - if (r >= 0) - cgroup_context_apply(c, u->cgroup_mask, u->cgroup_path); - return r; } diff --git a/src/core/cgroup.h b/src/core/cgroup.h index 0a079e909d..25f40f7b62 100644 --- a/src/core/cgroup.h +++ b/src/core/cgroup.h @@ -113,3 +113,5 @@ int manager_notify_cgroup_empty(Manager *m, const char *group); const char* cgroup_device_policy_to_string(CGroupDevicePolicy i) _const_; CGroupDevicePolicy cgroup_device_policy_from_string(const char *s) _pure_; + +void unit_update_member_masks(Unit *u); diff --git a/src/core/unit.c b/src/core/unit.c index 1173f0b160..894485f6d7 100644 --- a/src/core/unit.c +++ b/src/core/unit.c @@ -741,7 +741,8 @@ void unit_dump(Unit *u, FILE *f, const char *prefix) { "%s\tSlice: %s\n" "%s\tCGroup: %s\n" "%s\tCGroup realized: %s\n" - "%s\tCGroup mask: 0x%x\n", + "%s\tCGroup mask: 0x%x\n" + "%s\tCGroup members mask: 0x%x\n", prefix, u->id, prefix, unit_description(u), prefix, strna(u->instance), @@ -757,7 +758,8 @@ void unit_dump(Unit *u, FILE *f, const char *prefix) { prefix, strna(unit_slice_name(u)), prefix, strna(u->cgroup_path), prefix, yes_no(u->cgroup_realized), - prefix, u->cgroup_mask); + prefix, u->cgroup_mask, + prefix, u->cgroup_members_mask); SET_FOREACH(t, u->names, i) fprintf(f, "%s\tName: %s\n", prefix, t); @@ -1025,6 +1027,8 @@ int unit_load(Unit *u) { goto fail; } + unit_update_member_masks(u); + r = unit_add_mount_links(u); if (r < 0) goto fail; diff --git a/src/core/unit.h b/src/core/unit.h index c58202bf0f..5b4f86c584 100644 --- a/src/core/unit.h +++ b/src/core/unit.h @@ -175,6 +175,7 @@ struct Unit { /* Counterparts in the cgroup filesystem */ char *cgroup_path; CGroupControllerMask cgroup_mask; + CGroupControllerMask cgroup_members_mask; UnitRef slice; -- cgit v1.2.3-54-g00ecf