-/*
- * GPL HEADER START
- *
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 only,
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License version 2 for more details (a copy is included
- * in the LICENSE file that accompanied this code).
- *
- * You should have received a copy of the GNU General Public License
- * version 2 along with this program; If not, see
- * http://www.gnu.org/licenses/gpl-2.0.html
- *
- * GPL HEADER END
- */
-/*
- * This file is part of Lustre, http://www.lustre.org/
- *
- * lustre/obdclass/lu_qos.c
- *
- * Lustre QoS.
- * These are the only exported functions, they provide some generic
- * infrastructure for object allocation QoS
- *
- */
-
-#define DEBUG_SUBSYSTEM S_CLASS
-
-#include <linux/module.h>
-#include <linux/list.h>
-#include <linux/random.h>
-#include <libcfs/libcfs.h>
-#include <libcfs/libcfs_hash.h> /* hash_long() */
-#include <libcfs/linux/linux-mem.h>
-#include <obd_class.h>
-#include <obd_support.h>
-#include <lustre_disk.h>
-#include <lustre_fid.h>
-#include <lu_object.h>
-
-void lu_qos_rr_init(struct lu_qos_rr *lqr)
-{
- spin_lock_init(&lqr->lqr_alloc);
- lqr->lqr_dirty = 1;
-}
-EXPORT_SYMBOL(lu_qos_rr_init);
-
-/**
- * Add a new target to Quality of Service (QoS) target table.
- *
- * Add a new MDT/OST target to the structure representing an OSS. Resort the
- * list of known MDSs/OSSs by the number of MDTs/OSTs attached to each MDS/OSS.
- * The MDS/OSS list is protected internally and no external locking is required.
- *
- * \param[in] qos lu_qos data
- * \param[in] ltd target description
- *
- * \retval 0 on success
- * \retval -ENOMEM on error
- */
-int lqos_add_tgt(struct lu_qos *qos, struct lu_tgt_desc *ltd)
-{
- struct lu_svr_qos *svr = NULL;
- struct lu_svr_qos *tempsvr;
- struct obd_export *exp = ltd->ltd_exp;
- int found = 0;
- __u32 id = 0;
- int rc = 0;
-
- ENTRY;
-
- down_write(&qos->lq_rw_sem);
- /*
- * a bit hacky approach to learn NID of corresponding connection
- * but there is no official API to access information like this
- * with OSD API.
- */
- list_for_each_entry(svr, &qos->lq_svr_list, lsq_svr_list) {
- if (obd_uuid_equals(&svr->lsq_uuid,
- &exp->exp_connection->c_remote_uuid)) {
- found++;
- break;
- }
- if (svr->lsq_id > id)
- id = svr->lsq_id;
- }
-
- if (!found) {
- OBD_ALLOC_PTR(svr);
- if (!svr)
- GOTO(out, rc = -ENOMEM);
- memcpy(&svr->lsq_uuid, &exp->exp_connection->c_remote_uuid,
- sizeof(svr->lsq_uuid));
- ++id;
- svr->lsq_id = id;
- } else {
- /* Assume we have to move this one */
- list_del(&svr->lsq_svr_list);
- }
-
- svr->lsq_tgt_count++;
- ltd->ltd_qos.ltq_svr = svr;
-
- CDEBUG(D_OTHER, "add tgt %s to server %s (%d targets)\n",
- obd_uuid2str(<d->ltd_uuid), obd_uuid2str(&svr->lsq_uuid),
- svr->lsq_tgt_count);
-
- /*
- * Add sorted by # of tgts. Find the first entry that we're
- * bigger than...
- */
- list_for_each_entry(tempsvr, &qos->lq_svr_list, lsq_svr_list) {
- if (svr->lsq_tgt_count > tempsvr->lsq_tgt_count)
- break;
- }
- /*
- * ...and add before it. If we're the first or smallest, tempsvr
- * points to the list head, and we add to the end.
- */
- list_add_tail(&svr->lsq_svr_list, &tempsvr->lsq_svr_list);
-
- qos->lq_dirty = 1;
- qos->lq_rr.lqr_dirty = 1;
-
-out:
- up_write(&qos->lq_rw_sem);
- RETURN(rc);
-}
-EXPORT_SYMBOL(lqos_add_tgt);
-
-/**
- * Remove MDT/OST target from QoS table.
- *
- * Removes given MDT/OST target from QoS table and releases related
- * MDS/OSS structure if no target remain on the MDS/OSS.
- *
- * \param[in] qos lu_qos data
- * \param[in] ltd target description
- *
- * \retval 0 on success
- * \retval -ENOENT if no server was found
- */
-int lqos_del_tgt(struct lu_qos *qos, struct lu_tgt_desc *ltd)
-{
- struct lu_svr_qos *svr;
- int rc = 0;
-
- ENTRY;
-
- down_write(&qos->lq_rw_sem);
- svr = ltd->ltd_qos.ltq_svr;
- if (!svr)
- GOTO(out, rc = -ENOENT);
-
- svr->lsq_tgt_count--;
- if (svr->lsq_tgt_count == 0) {
- CDEBUG(D_OTHER, "removing server %s\n",
- obd_uuid2str(&svr->lsq_uuid));
- list_del(&svr->lsq_svr_list);
- ltd->ltd_qos.ltq_svr = NULL;
- OBD_FREE_PTR(svr);
- }
-
- qos->lq_dirty = 1;
- qos->lq_rr.lqr_dirty = 1;
-out:
- up_write(&qos->lq_rw_sem);
- RETURN(rc);
-}
-EXPORT_SYMBOL(lqos_del_tgt);
-
-/**
- * lu_prandom_u64_max - returns a pseudo-random u64 number in interval
- * [0, ep_ro)
- *
- * \param[in] ep_ro right open interval endpoint
- *
- * \retval a pseudo-random 64-bit number that is in interval [0, ep_ro).
- */
-u64 lu_prandom_u64_max(u64 ep_ro)
-{
- u64 rand = 0;
-
- if (ep_ro) {
-#if BITS_PER_LONG == 32
- /*
- * If ep_ro > 32-bit, first generate the high
- * 32 bits of the random number, then add in the low
- * 32 bits (truncated to the upper limit, if needed)
- */
- if (ep_ro > 0xffffffffULL)
- rand = prandom_u32_max((u32)(ep_ro >> 32)) << 32;
-
- if (rand == (ep_ro & 0xffffffff00000000ULL))
- rand |= prandom_u32_max((u32)ep_ro);
- else
- rand |= prandom_u32();
-#else
- rand = ((u64)prandom_u32() << 32 | prandom_u32()) % ep_ro;
-#endif
- }
-
- return rand;
-}
-EXPORT_SYMBOL(lu_prandom_u64_max);
-
-static inline __u64 tgt_statfs_bavail(struct lu_tgt_desc *tgt)
-{
- struct obd_statfs *statfs = &tgt->ltd_statfs;
-
- return statfs->os_bavail * statfs->os_bsize;
-}
-
-static inline __u64 tgt_statfs_iavail(struct lu_tgt_desc *tgt)
-{
- return tgt->ltd_statfs.os_ffree;
-}
-
-/**
- * Calculate penalties per-tgt and per-server
- *
- * Re-calculate penalties when the configuration changes, active targets
- * change and after statfs refresh (all these are reflected by lq_dirty flag).
- * On every tgt and server: decay the penalty by half for every 8x the update
- * interval that the device has been idle. That gives lots of time for the
- * statfs information to be updated (which the penalty is only a proxy for),
- * and avoids penalizing server/tgt under light load.
- * See lqos_calc_weight() for how penalties are factored into the weight.
- *
- * \param[in] qos lu_qos
- * \param[in] ltd lu_tgt_descs
- * \param[in] active_tgt_nr active tgt number
- * \param[in] maxage qos max age
- * \param[in] is_mdt MDT will count inode usage
- *
- * \retval 0 on success
- * \retval -EAGAIN the number of tgt isn't enough or all tgt spaces are
- * almost the same
- */
-int lqos_calc_penalties(struct lu_qos *qos, struct lu_tgt_descs *ltd,
- __u32 active_tgt_nr, __u32 maxage, bool is_mdt)
-{
- struct lu_tgt_desc *tgt;
- struct lu_svr_qos *svr;
- __u64 ba_max, ba_min, ba;
- __u64 ia_max, ia_min, ia = 1;
- __u32 num_active;
- int prio_wide;
- time64_t now, age;
- int rc;
-
- ENTRY;
-
- if (!qos->lq_dirty)
- GOTO(out, rc = 0);
-
- num_active = active_tgt_nr - 1;
- if (num_active < 1)
- GOTO(out, rc = -EAGAIN);
-
- /* find bavail on each server */
- list_for_each_entry(svr, &qos->lq_svr_list, lsq_svr_list) {
- svr->lsq_bavail = 0;
- /* if inode is not counted, set to 1 to ignore */
- svr->lsq_iavail = is_mdt ? 0 : 1;
- }
- qos->lq_active_svr_count = 0;
-
- /*
- * How badly user wants to select targets "widely" (not recently chosen
- * and not on recent MDS's). As opposed to "freely" (free space avail.)
- * 0-256
- */
- prio_wide = 256 - qos->lq_prio_free;
-
- ba_min = (__u64)(-1);
- ba_max = 0;
- ia_min = (__u64)(-1);
- ia_max = 0;
- now = ktime_get_real_seconds();
-
- /* Calculate server penalty per object */
- ltd_foreach_tgt(ltd, tgt) {
- if (!tgt->ltd_active)
- continue;
-
- /* when inode is counted, bavail >> 16 to avoid overflow */
- ba = tgt_statfs_bavail(tgt);
- if (is_mdt)
- ba >>= 16;
- else
- ba >>= 8;
- if (!ba)
- continue;
-
- ba_min = min(ba, ba_min);
- ba_max = max(ba, ba_max);
-
- /* Count the number of usable servers */
- if (tgt->ltd_qos.ltq_svr->lsq_bavail == 0)
- qos->lq_active_svr_count++;
- tgt->ltd_qos.ltq_svr->lsq_bavail += ba;
-
- if (is_mdt) {
- /* iavail >> 8 to avoid overflow */
- ia = tgt_statfs_iavail(tgt) >> 8;
- if (!ia)
- continue;
-
- ia_min = min(ia, ia_min);
- ia_max = max(ia, ia_max);
-
- tgt->ltd_qos.ltq_svr->lsq_iavail += ia;
- }
-
- /*
- * per-tgt penalty is
- * prio * bavail * iavail / (num_tgt - 1) / 2
- */
- tgt->ltd_qos.ltq_penalty_per_obj = prio_wide * ba * ia >> 8;
- do_div(tgt->ltd_qos.ltq_penalty_per_obj, num_active);
- tgt->ltd_qos.ltq_penalty_per_obj >>= 1;
-
- age = (now - tgt->ltd_qos.ltq_used) >> 3;
- if (qos->lq_reset || age > 32 * maxage)
- tgt->ltd_qos.ltq_penalty = 0;
- else if (age > maxage)
- /* Decay tgt penalty. */
- tgt->ltd_qos.ltq_penalty >>= (age / maxage);
- }
-
- num_active = qos->lq_active_svr_count - 1;
- if (num_active < 1) {
- /*
- * If there's only 1 server, we can't penalize it, so instead
- * we have to double the tgt penalty
- */
- num_active = 1;
- ltd_foreach_tgt(ltd, tgt) {
- if (!tgt->ltd_active)
- continue;
-
- tgt->ltd_qos.ltq_penalty_per_obj <<= 1;
- }
- }
-
- /*
- * Per-server penalty is
- * prio * bavail * iavail / server_tgts / (num_svr - 1) / 2
- */
- list_for_each_entry(svr, &qos->lq_svr_list, lsq_svr_list) {
- ba = svr->lsq_bavail;
- ia = svr->lsq_iavail;
- svr->lsq_penalty_per_obj = prio_wide * ba * ia >> 8;
- do_div(ba, svr->lsq_tgt_count * num_active);
- svr->lsq_penalty_per_obj >>= 1;
-
- age = (now - svr->lsq_used) >> 3;
- if (qos->lq_reset || age > 32 * maxage)
- svr->lsq_penalty = 0;
- else if (age > maxage)
- /* Decay server penalty. */
- svr->lsq_penalty >>= age / maxage;
- }
-
- qos->lq_dirty = 0;
- qos->lq_reset = 0;
-
- /*
- * If each tgt has almost same free space, do rr allocation for better
- * creation performance
- */
- qos->lq_same_space = 0;
- if ((ba_max * (256 - qos->lq_threshold_rr)) >> 8 < ba_min &&
- (ia_max * (256 - qos->lq_threshold_rr)) >> 8 < ia_min) {
- qos->lq_same_space = 1;
- /* Reset weights for the next time we enter qos mode */
- qos->lq_reset = 1;
- }
- rc = 0;
-
-out:
- if (!rc && qos->lq_same_space)
- RETURN(-EAGAIN);
-
- RETURN(rc);
-}
-EXPORT_SYMBOL(lqos_calc_penalties);
-
-bool lqos_is_usable(struct lu_qos *qos, __u32 active_tgt_nr)
-{
- if (!qos->lq_dirty && qos->lq_same_space)
- return false;
-
- if (active_tgt_nr < 2)
- return false;
-
- return true;
-}
-EXPORT_SYMBOL(lqos_is_usable);
-
-/**
- * Calculate weight for a given tgt.
- *
- * The final tgt weight is bavail >> 16 * iavail >> 8 minus the tgt and server
- * penalties. See lqos_calc_ppts() for how penalties are calculated.
- *
- * \param[in] tgt target descriptor
- */
-void lqos_calc_weight(struct lu_tgt_desc *tgt)
-{
- struct lu_tgt_qos *ltq = &tgt->ltd_qos;
- __u64 temp, temp2;
-
- temp = (tgt_statfs_bavail(tgt) >> 16) * (tgt_statfs_iavail(tgt) >> 8);
- temp2 = ltq->ltq_penalty + ltq->ltq_svr->lsq_penalty;
- if (temp < temp2)
- ltq->ltq_weight = 0;
- else
- ltq->ltq_weight = temp - temp2;
-}
-EXPORT_SYMBOL(lqos_calc_weight);
-
-/**
- * Re-calculate weights.
- *
- * The function is called when some target was used for a new object. In
- * this case we should re-calculate all the weights to keep new allocations
- * balanced well.
- *
- * \param[in] qos lu_qos
- * \param[in] ltd lu_tgt_descs
- * \param[in] tgt target where a new object was placed
- * \param[in] active_tgt_nr active tgt number
- * \param[out] total_wt new total weight for the pool
- *
- * \retval 0
- */
-int lqos_recalc_weight(struct lu_qos *qos, struct lu_tgt_descs *ltd,
- struct lu_tgt_desc *tgt, __u32 active_tgt_nr,
- __u64 *total_wt)
-{
- struct lu_tgt_qos *ltq;
- struct lu_svr_qos *svr;
-
- ENTRY;
-
- ltq = &tgt->ltd_qos;
- LASSERT(ltq);
-
- /* Don't allocate on this device anymore, until the next alloc_qos */
- ltq->ltq_usable = 0;
-
- svr = ltq->ltq_svr;
-
- /*
- * Decay old penalty by half (we're adding max penalty, and don't
- * want it to run away.)
- */
- ltq->ltq_penalty >>= 1;
- svr->lsq_penalty >>= 1;
-
- /* mark the server and tgt as recently used */
- ltq->ltq_used = svr->lsq_used = ktime_get_real_seconds();
-
- /* Set max penalties for this tgt and server */
- ltq->ltq_penalty += ltq->ltq_penalty_per_obj * active_tgt_nr;
- svr->lsq_penalty += svr->lsq_penalty_per_obj * active_tgt_nr;
-
- /* Decrease all MDS penalties */
- list_for_each_entry(svr, &qos->lq_svr_list, lsq_svr_list) {
- if (svr->lsq_penalty < svr->lsq_penalty_per_obj)
- svr->lsq_penalty = 0;
- else
- svr->lsq_penalty -= svr->lsq_penalty_per_obj;
- }
-
- *total_wt = 0;
- /* Decrease all tgt penalties */
- ltd_foreach_tgt(ltd, tgt) {
- if (!tgt->ltd_active)
- continue;
-
- if (ltq->ltq_penalty < ltq->ltq_penalty_per_obj)
- ltq->ltq_penalty = 0;
- else
- ltq->ltq_penalty -= ltq->ltq_penalty_per_obj;
-
- lqos_calc_weight(tgt);
-
- /* Recalc the total weight of usable osts */
- if (ltq->ltq_usable)
- *total_wt += ltq->ltq_weight;
-
- CDEBUG(D_OTHER, "recalc tgt %d usable=%d avail=%llu"
- " tgtppo=%llu tgtp=%llu svrppo=%llu"
- " svrp=%llu wt=%llu\n",
- tgt->ltd_index, ltq->ltq_usable,
- tgt_statfs_bavail(tgt) >> 10,
- ltq->ltq_penalty_per_obj >> 10,
- ltq->ltq_penalty >> 10,
- ltq->ltq_svr->lsq_penalty_per_obj >> 10,
- ltq->ltq_svr->lsq_penalty >> 10,
- ltq->ltq_weight >> 10);
- }
-
- RETURN(0);
-}
-EXPORT_SYMBOL(lqos_recalc_weight);
git://git.whamcloud.com / fs / lustre-release.git / commitdiff