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| author | attilio <attilio@FreeBSD.org> | 2012-01-28 14:00:21 +0000 |
|---|---|---|
| committer | attilio <attilio@FreeBSD.org> | 2012-01-28 14:00:21 +0000 |
| commit | 1521eb447956638ea699e9468527cdcbd2b28659 (patch) | |
| tree | 51e3a468764edd7cbdf62d40b3ad43948e5ccd09 /sys/sys | |
| parent | a1d2d789bd56b6e4fbadcea3ce4cab8cd7fed168 (diff) | |
| download | FreeBSD-src-1521eb447956638ea699e9468527cdcbd2b28659.zip FreeBSD-src-1521eb447956638ea699e9468527cdcbd2b28659.tar.gz | |
Avoid to check the same cache line/variable from all the locking
primitives by breaking stop_scheduler into a per-thread variable.
Also, store the new td_stopsched very close to td_*locks members as
they will be accessed mostly in the same codepaths as td_stopsched and
this results in avoiding a further cache-line pollution, possibly.
STOP_SCHEDULER() was pondered to use a new 'thread' argument, in order to
take advantage of already cached curthread, but in the end there should
not really be a performance benefit, while introducing a KPI breakage.
In collabouration with: flo
Reviewed by: avg
MFC after: 3 months (or never)
X-MFC: r228424
Diffstat (limited to 'sys/sys')
| -rw-r--r-- | sys/sys/proc.h | 1 | ||||
| -rw-r--r-- | sys/sys/systm.h | 3 |
2 files changed, 2 insertions, 2 deletions
diff --git a/sys/sys/proc.h b/sys/sys/proc.h index ba00a88..76f3355 100644 --- a/sys/sys/proc.h +++ b/sys/sys/proc.h @@ -235,6 +235,7 @@ struct thread { short td_locks; /* (k) Count of non-spin locks. */ short td_rw_rlocks; /* (k) Count of rwlock read locks. */ short td_lk_slocks; /* (k) Count of lockmgr shared locks. */ + short td_stopsched; /* (k) Scheduler stopped. */ struct turnstile *td_blocked; /* (t) Lock thread is blocked on. */ const char *td_lockname; /* (t) Name of lock blocked on. */ LIST_HEAD(, turnstile) td_contested; /* (q) Contested locks. */ diff --git a/sys/sys/systm.h b/sys/sys/systm.h index e5d60d4..47b974a 100644 --- a/sys/sys/systm.h +++ b/sys/sys/systm.h @@ -47,7 +47,6 @@ extern int cold; /* nonzero if we are doing a cold boot */ extern int rebooting; /* kern_reboot() has been called. */ -extern int stop_scheduler; /* only one thread runs after panic */ extern const char *panicstr; /* panic message */ extern char version[]; /* system version */ extern char copyright[]; /* system copyright */ @@ -113,7 +112,7 @@ enum VM_GUEST { VM_GUEST_NO = 0, VM_GUEST_VM, VM_GUEST_XEN }; * Otherwise, the kernel will deadlock since the scheduler isn't * going to run the thread that holds any lock we need. */ -#define SCHEDULER_STOPPED() __predict_false(stop_scheduler) +#define SCHEDULER_STOPPED() __predict_false(curthread->td_stopsched) /* * XXX the hints declarations are even more misplaced than most declarations |
