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| author | Rickard Green <[email protected]> | 2010-11-26 13:37:23 +0100 |
|---|---|---|
| committer | Rickard Green <[email protected]> | 2010-12-01 11:18:24 +0100 |
| commit | 7136d5ed3f68414ad122ef39cb51fe4c80011be8 (patch) | |
| tree | aa0813e40917c12e8803e32c4f6089ba12e69e9d /erts/emulator | |
| parent | 17224a3d31d25ce6daa4de63b52b26bee9564bcd (diff) | |
| download | otp-7136d5ed3f68414ad122ef39cb51fe4c80011be8.tar.gz otp-7136d5ed3f68414ad122ef39cb51fe4c80011be8.tar.bz2 otp-7136d5ed3f68414ad122ef39cb51fe4c80011be8.zip | |
Prevent wrapping of values used during load balancing
Some integer values used during load balancing could
under rare circumstances wrap causing a load unbalance
between schedulers.
Diffstat (limited to 'erts/emulator')
| -rw-r--r-- | erts/emulator/beam/erl_process.c | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c index 901167a315..6a647848a2 100644 --- a/erts/emulator/beam/erl_process.c +++ b/erts/emulator/beam/erl_process.c @@ -1886,6 +1886,9 @@ do { \ static void check_balance(ErtsRunQueue *c_rq) { +#if ERTS_MAX_PROCESSES >= (1 << 27) +# error check_balance() assumes ERTS_MAX_PROCESS < (1 << 27) +#endif ErtsRunQueueBalance avg = {0}; Sint64 scheds_reds, full_scheds_reds; int forced, active, current_active, oowc, half_full_scheds, full_scheds, @@ -2009,12 +2012,14 @@ check_balance(ErtsRunQueue *c_rq) run_queue_info[qix].prio[pix].avail = 0; } else { - int xreds = 0; - int procreds = treds; - procreds -= run_queue_info[qix].prio[ERTS_PORT_PRIO_LEVEL].reds; + Sint64 xreds = 0; + Sint64 procreds = treds; + procreds -= + ((Sint64) + run_queue_info[qix].prio[ERTS_PORT_PRIO_LEVEL].reds); for (pix = 0; pix < ERTS_NO_PROC_PRIO_LEVELS; pix++) { - int av; + Sint64 av; if (xreds == 0) av = 100; @@ -2025,9 +2030,10 @@ check_balance(ErtsRunQueue *c_rq) if (av == 0) av = 1; } - run_queue_info[qix].prio[pix].avail = av; + run_queue_info[qix].prio[pix].avail = (int) av; + ASSERT(run_queue_info[qix].prio[pix].avail >= 0); if (pix < PRIORITY_NORMAL) /* ie., max or high */ - xreds += run_queue_info[qix].prio[pix].reds; + xreds += (Sint64) run_queue_info[qix].prio[pix].reds; } run_queue_info[qix].prio[ERTS_PORT_PRIO_LEVEL].avail = 100; } @@ -2132,7 +2138,8 @@ check_balance(ErtsRunQueue *c_rq) if (max_len != 0) { int avail = avg.prio[pix].avail; if (avail != 0) { - max_len = ((100*max_len - 1) / avail) + 1; + max_len = (int) ((100*((Sint64) max_len) - 1) + / ((Sint64) avail)) + 1; avg.prio[pix].max_len = max_len; ASSERT(max_len >= 0); } @@ -2149,9 +2156,10 @@ check_balance(ErtsRunQueue *c_rq) || run_queue_info[qix].prio[pix].avail == 0) limit = 0; else - limit = (((avg.prio[pix].max_len - * run_queue_info[qix].prio[pix].avail) - 1) - / 100 + 1); + limit = (int) (((((Sint64) avg.prio[pix].max_len) + * ((Sint64) run_queue_info[qix].prio[pix].avail)) + - 1) + / 100 + 1); run_queue_info[qix].prio[pix].migration_limit = limit; } } |