Allow user to specify that rmids used by a cgroup/event cannot be stolen. The pmonrs that are marked with CMT_UF_NOSTEAL_RMID will never lose a valid rmid once they have receive one.
Signed-off-by: David Carrillo-Cisneros <[email protected]> --- arch/x86/events/intel/cmt.c | 10 +++++++++- arch/x86/events/intel/cmt.h | 5 ++++- 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/arch/x86/events/intel/cmt.c b/arch/x86/events/intel/cmt.c index e677511..8cbcbc6 100644 --- a/arch/x86/events/intel/cmt.c +++ b/arch/x86/events/intel/cmt.c @@ -41,7 +41,7 @@ static struct monr *monr_hrchy_root; /* Flags for root monr and all its pmonrs while being monitored. */ static enum cmt_user_flags root_monr_uflags = - CMT_UF_HAS_USER | CMT_UF_NOLAZY_RMID; + CMT_UF_HAS_USER | CMT_UF_NOSTEAL_RMID | CMT_UF_NOLAZY_RMID; /* Auxiliar flags */ static enum cmt_user_flags *pkg_uflags_zeroes; @@ -499,6 +499,7 @@ static void monr_dealloc(struct monr *monr) */ if (WARN_ON_ONCE(!(monr->flags & CMT_MONR_ZOMBIE)) || WARN_ON_ONCE(monr->nr_has_user) || + WARN_ON_ONCE(monr->nr_nosteal_rmid) || WARN_ON_ONCE(monr->nr_nolazy_rmid) || WARN_ON_ONCE(monr->mon_cgrp) || WARN_ON_ONCE(monr->mon_events)) @@ -743,10 +744,13 @@ static bool monr_account_uflags(struct monr *monr, if (uflags & CMT_UF_HAS_USER) monr->nr_has_user += account ? 1 : -1; + if (uflags & CMT_UF_NOSTEAL_RMID) + monr->nr_nosteal_rmid += account ? 1 : -1; if (uflags & CMT_UF_NOLAZY_RMID) monr->nr_nolazy_rmid += account ? 1 : -1; monr->uflags = (monr->nr_has_user ? CMT_UF_HAS_USER : 0) | + (monr->nr_nosteal_rmid ? CMT_UF_NOSTEAL_RMID : 0) | (monr->nr_nolazy_rmid ? CMT_UF_NOLAZY_RMID : 0); return old_flags != monr->uflags; @@ -1400,6 +1404,10 @@ static bool can_steal_rmid(struct pmonr *pmonr) u64 last_all_active, next_steal_time, last_pmonr_active; last_all_active = atomic64_read(&monr->last_rmid_recoup); + + if (pmonr_uflags(pmonr) & CMT_UF_NOSTEAL_RMID) + return false; + /* * Can steal if no pmonr has been stolen or all not Unused have been * in Active state for long enough. diff --git a/arch/x86/events/intel/cmt.h b/arch/x86/events/intel/cmt.h index 872cce0..c377076 100644 --- a/arch/x86/events/intel/cmt.h +++ b/arch/x86/events/intel/cmt.h @@ -290,7 +290,8 @@ enum cmt_user_flags { /* if no has_user other flags are meaningless. */ CMT_UF_HAS_USER = BIT(0), /* has cgroup or event users */ CMT_UF_NOLAZY_RMID = BIT(1), /* try to obtain rmid on creation */ - CMT_UF_MAX = BIT(2) - 1, + CMT_UF_NOSTEAL_RMID = BIT(2), /* do not steal this rmid */ + CMT_UF_MAX = BIT(3) - 1, CMT_UF_ERROR = CMT_UF_MAX + 1, }; @@ -309,6 +310,7 @@ enum cmt_user_flags { * monr is monitoring in all required packages. * @flags: monr_flags. * @nr_has_user: nr of CMT_UF_HAS_USER set in events in mon_events. + * @nr_nosteal_user: nr of CMT_UF_NOSTEAL_RMID set in events in mon_events. * @nr_nolazy_user: nr of CMT_UF_NOLAZY_RMID set in events in mon_events. * @uflags: monr level cmt_user_flags, or'ed with pkg_uflags. * @pkg_uflags: package level cmt_user_flags, each entry is used as @@ -335,6 +337,7 @@ struct monr { enum monr_flags flags; int nr_has_user; + int nr_nosteal_rmid; int nr_nolazy_rmid; enum cmt_user_flags uflags; enum cmt_user_flags pkg_uflags[]; -- 2.8.0.rc3.226.g39d4020
