diff options
Diffstat (limited to 'db-4.8.30/mp/mp_trickle.c')
-rw-r--r-- | db-4.8.30/mp/mp_trickle.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/db-4.8.30/mp/mp_trickle.c b/db-4.8.30/mp/mp_trickle.c new file mode 100644 index 0000000..e92e788 --- /dev/null +++ b/db-4.8.30/mp/mp_trickle.c @@ -0,0 +1,112 @@ +/*- + * See the file LICENSE for redistribution information. + * + * Copyright (c) 1996-2009 Oracle. All rights reserved. + * + * $Id$ + */ + +#include "db_config.h" + +#include "db_int.h" +#include "dbinc/log.h" +#include "dbinc/mp.h" + +static int __memp_trickle __P((ENV *, int, int *)); + +/* + * __memp_trickle_pp -- + * ENV->memp_trickle pre/post processing. + * + * PUBLIC: int __memp_trickle_pp __P((DB_ENV *, int, int *)); + */ +int +__memp_trickle_pp(dbenv, pct, nwrotep) + DB_ENV *dbenv; + int pct, *nwrotep; +{ + DB_THREAD_INFO *ip; + ENV *env; + int ret; + + env = dbenv->env; + + ENV_REQUIRES_CONFIG(env, + env->mp_handle, "memp_trickle", DB_INIT_MPOOL); + + ENV_ENTER(env, ip); + REPLICATION_WRAP(env, (__memp_trickle(env, pct, nwrotep)), 0, ret); + ENV_LEAVE(env, ip); + return (ret); +} + +/* + * __memp_trickle -- + * ENV->memp_trickle. + */ +static int +__memp_trickle(env, pct, nwrotep) + ENV *env; + int pct, *nwrotep; +{ + DB_MPOOL *dbmp; + MPOOL *c_mp, *mp; + u_int32_t clean, dirty, i, need_clean, total, dtmp, wrote; + int ret; + + dbmp = env->mp_handle; + mp = dbmp->reginfo[0].primary; + + if (nwrotep != NULL) + *nwrotep = 0; + + if (pct < 1 || pct > 100) { + __db_errx(env, + "DB_ENV->memp_trickle: %d: percent must be between 1 and 100", + pct); + return (EINVAL); + } + + /* + * Loop through the caches counting total/dirty buffers. + * + * XXX + * Using hash_page_dirty is our only choice at the moment, but it's not + * as correct as we might like in the presence of pools having more + * than one page size, as a free 512B buffer may not be equivalent to + * having a free 8KB buffer. + */ + for (ret = 0, i = dirty = total = 0; i < mp->nreg; ++i) { + c_mp = dbmp->reginfo[i].primary; + total += c_mp->stat.st_pages; + __memp_stat_hash(&dbmp->reginfo[i], c_mp, &dtmp); + dirty += dtmp; + } + + /* + * If there are sufficient clean buffers, no buffers or no dirty + * buffers, we're done. + */ + if (total == 0 || dirty == 0) + return (0); + + /* + * The total number of pages is an exact number, but the dirty page + * count can change while we're walking the hash buckets, and it's + * even possible the dirty page count ends up larger than the total + * number of pages. + */ + clean = total > dirty ? total - dirty : 0; + need_clean = (total * (u_int)pct) / 100; + if (clean >= need_clean) + return (0); + + need_clean -= clean; + ret = __memp_sync_int(env, NULL, + need_clean, DB_SYNC_TRICKLE | DB_SYNC_INTERRUPT_OK, &wrote, NULL); + STAT((mp->stat.st_page_trickle += wrote)); + if (nwrotep != NULL) + *nwrotep = (int)wrote; + + return (ret); +} |