1039 lines
28 KiB
C
1039 lines
28 KiB
C
/*
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* GPL HEADER START
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*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 only,
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License version 2 for more details (a copy is included
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* in the LICENSE file that accompanied this code).
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*
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* You should have received a copy of the GNU General Public License
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* version 2 along with this program; If not, see
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* http://www.gnu.org/licenses/gpl-2.0.html
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*
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* GPL HEADER END
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*/
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/*
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* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
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* Use is subject to license terms.
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*
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* Copyright (c) 2011, 2015, Intel Corporation.
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*/
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/*
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* This file is part of Lustre, http://www.lustre.org/
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* Lustre is a trademark of Sun Microsystems, Inc.
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*
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* Implementation of cl_page for OSC layer.
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*
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* Author: Nikita Danilov <nikita.danilov@sun.com>
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* Author: Jinshan Xiong <jinshan.xiong@intel.com>
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*/
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#define DEBUG_SUBSYSTEM S_OSC
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#include <linux/math64.h>
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#include "osc_cl_internal.h"
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static void osc_lru_del(struct client_obd *cli, struct osc_page *opg);
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static void osc_lru_use(struct client_obd *cli, struct osc_page *opg);
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static int osc_lru_reserve(const struct lu_env *env, struct osc_object *obj,
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struct osc_page *opg);
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/** \addtogroup osc
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* @{
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*/
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/*****************************************************************************
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*
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* Page operations.
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*
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*/
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static void osc_page_transfer_get(struct osc_page *opg, const char *label)
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{
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struct cl_page *page = opg->ops_cl.cpl_page;
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LASSERT(!opg->ops_transfer_pinned);
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cl_page_get(page);
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lu_ref_add_atomic(&page->cp_reference, label, page);
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opg->ops_transfer_pinned = 1;
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}
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static void osc_page_transfer_put(const struct lu_env *env,
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struct osc_page *opg)
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{
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struct cl_page *page = opg->ops_cl.cpl_page;
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if (opg->ops_transfer_pinned) {
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opg->ops_transfer_pinned = 0;
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lu_ref_del(&page->cp_reference, "transfer", page);
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cl_page_put(env, page);
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}
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}
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/**
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* This is called once for every page when it is submitted for a transfer
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* either opportunistic (osc_page_cache_add()), or immediate
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* (osc_page_submit()).
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*/
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static void osc_page_transfer_add(const struct lu_env *env,
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struct osc_page *opg, enum cl_req_type crt)
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{
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struct osc_object *obj = cl2osc(opg->ops_cl.cpl_obj);
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osc_lru_use(osc_cli(obj), opg);
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}
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int osc_page_cache_add(const struct lu_env *env,
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const struct cl_page_slice *slice, struct cl_io *io)
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{
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struct osc_page *opg = cl2osc_page(slice);
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int result;
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osc_page_transfer_get(opg, "transfer\0cache");
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result = osc_queue_async_io(env, io, opg);
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if (result != 0)
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osc_page_transfer_put(env, opg);
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else
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osc_page_transfer_add(env, opg, CRT_WRITE);
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return result;
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}
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void osc_index2policy(union ldlm_policy_data *policy,
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const struct cl_object *obj,
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pgoff_t start, pgoff_t end)
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{
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memset(policy, 0, sizeof(*policy));
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policy->l_extent.start = cl_offset(obj, start);
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policy->l_extent.end = cl_offset(obj, end + 1) - 1;
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}
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static const char *osc_list(struct list_head *head)
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{
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return list_empty(head) ? "-" : "+";
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}
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static inline unsigned long osc_submit_duration(struct osc_page *opg)
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{
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if (opg->ops_submit_time == 0)
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return 0;
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return (cfs_time_current() - opg->ops_submit_time);
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}
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static int osc_page_print(const struct lu_env *env,
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const struct cl_page_slice *slice,
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void *cookie, lu_printer_t printer)
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{
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struct osc_page *opg = cl2osc_page(slice);
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struct osc_async_page *oap = &opg->ops_oap;
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struct osc_object *obj = cl2osc(slice->cpl_obj);
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struct client_obd *cli = &osc_export(obj)->exp_obd->u.cli;
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return (*printer)(env, cookie, LUSTRE_OSC_NAME "-page@%p %lu: 1< %#x %d %u %s %s > 2< %llu %u %u %#x %#x | %p %p %p > 3< %d %lu %d > 4< %d %d %d %lu %s | %s %s %s %s > 5< %s %s %s %s | %d %s | %d %s %s>\n",
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opg, osc_index(opg),
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/* 1 */
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oap->oap_magic, oap->oap_cmd,
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oap->oap_interrupted,
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osc_list(&oap->oap_pending_item),
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osc_list(&oap->oap_rpc_item),
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/* 2 */
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oap->oap_obj_off, oap->oap_page_off, oap->oap_count,
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oap->oap_async_flags, oap->oap_brw_flags,
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oap->oap_request, oap->oap_cli, obj,
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/* 3 */
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opg->ops_transfer_pinned,
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osc_submit_duration(opg), opg->ops_srvlock,
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/* 4 */
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cli->cl_r_in_flight, cli->cl_w_in_flight,
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cli->cl_max_rpcs_in_flight,
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cli->cl_avail_grant,
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osc_list(&cli->cl_cache_waiters),
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osc_list(&cli->cl_loi_ready_list),
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osc_list(&cli->cl_loi_hp_ready_list),
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osc_list(&cli->cl_loi_write_list),
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osc_list(&cli->cl_loi_read_list),
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/* 5 */
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osc_list(&obj->oo_ready_item),
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osc_list(&obj->oo_hp_ready_item),
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osc_list(&obj->oo_write_item),
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osc_list(&obj->oo_read_item),
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atomic_read(&obj->oo_nr_reads),
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osc_list(&obj->oo_reading_exts),
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atomic_read(&obj->oo_nr_writes),
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osc_list(&obj->oo_hp_exts),
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osc_list(&obj->oo_urgent_exts));
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}
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static void osc_page_delete(const struct lu_env *env,
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const struct cl_page_slice *slice)
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{
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struct osc_page *opg = cl2osc_page(slice);
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struct osc_object *obj = cl2osc(opg->ops_cl.cpl_obj);
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int rc;
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CDEBUG(D_TRACE, "%p\n", opg);
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osc_page_transfer_put(env, opg);
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rc = osc_teardown_async_page(env, obj, opg);
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if (rc) {
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CL_PAGE_DEBUG(D_ERROR, env, slice->cpl_page,
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"Trying to teardown failed: %d\n", rc);
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LASSERT(0);
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}
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osc_lru_del(osc_cli(obj), opg);
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if (slice->cpl_page->cp_type == CPT_CACHEABLE) {
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void *value;
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spin_lock(&obj->oo_tree_lock);
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value = radix_tree_delete(&obj->oo_tree, osc_index(opg));
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if (value)
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--obj->oo_npages;
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spin_unlock(&obj->oo_tree_lock);
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LASSERT(ergo(value, value == opg));
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}
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}
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static void osc_page_clip(const struct lu_env *env,
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const struct cl_page_slice *slice, int from, int to)
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{
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struct osc_page *opg = cl2osc_page(slice);
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struct osc_async_page *oap = &opg->ops_oap;
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opg->ops_from = from;
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opg->ops_to = to;
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spin_lock(&oap->oap_lock);
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oap->oap_async_flags |= ASYNC_COUNT_STABLE;
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spin_unlock(&oap->oap_lock);
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}
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static int osc_page_cancel(const struct lu_env *env,
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const struct cl_page_slice *slice)
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{
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struct osc_page *opg = cl2osc_page(slice);
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int rc = 0;
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/* Check if the transferring against this page
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* is completed, or not even queued.
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*/
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if (opg->ops_transfer_pinned)
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/* FIXME: may not be interrupted.. */
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rc = osc_cancel_async_page(env, opg);
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LASSERT(ergo(rc == 0, opg->ops_transfer_pinned == 0));
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return rc;
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}
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static int osc_page_flush(const struct lu_env *env,
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const struct cl_page_slice *slice,
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struct cl_io *io)
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{
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struct osc_page *opg = cl2osc_page(slice);
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int rc;
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rc = osc_flush_async_page(env, io, opg);
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return rc;
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}
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static const struct cl_page_operations osc_page_ops = {
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.cpo_print = osc_page_print,
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.cpo_delete = osc_page_delete,
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.cpo_clip = osc_page_clip,
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.cpo_cancel = osc_page_cancel,
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.cpo_flush = osc_page_flush
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};
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int osc_page_init(const struct lu_env *env, struct cl_object *obj,
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struct cl_page *page, pgoff_t index)
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{
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struct osc_object *osc = cl2osc(obj);
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struct osc_page *opg = cl_object_page_slice(obj, page);
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int result;
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opg->ops_from = 0;
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opg->ops_to = PAGE_SIZE;
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result = osc_prep_async_page(osc, opg, page->cp_vmpage,
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cl_offset(obj, index));
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if (result == 0) {
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struct osc_io *oio = osc_env_io(env);
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opg->ops_srvlock = osc_io_srvlock(oio);
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cl_page_slice_add(page, &opg->ops_cl, obj, index,
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&osc_page_ops);
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}
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INIT_LIST_HEAD(&opg->ops_lru);
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/* reserve an LRU space for this page */
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if (page->cp_type == CPT_CACHEABLE && result == 0) {
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result = osc_lru_reserve(env, osc, opg);
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if (result == 0) {
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spin_lock(&osc->oo_tree_lock);
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result = radix_tree_insert(&osc->oo_tree, index, opg);
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if (result == 0)
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++osc->oo_npages;
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spin_unlock(&osc->oo_tree_lock);
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LASSERT(result == 0);
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}
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}
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return result;
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}
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/**
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* Helper function called by osc_io_submit() for every page in an immediate
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* transfer (i.e., transferred synchronously).
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*/
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void osc_page_submit(const struct lu_env *env, struct osc_page *opg,
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enum cl_req_type crt, int brw_flags)
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{
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struct osc_async_page *oap = &opg->ops_oap;
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LASSERTF(oap->oap_magic == OAP_MAGIC, "Bad oap magic: oap %p, magic 0x%x\n",
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oap, oap->oap_magic);
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LASSERT(oap->oap_async_flags & ASYNC_READY);
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LASSERT(oap->oap_async_flags & ASYNC_COUNT_STABLE);
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oap->oap_cmd = crt == CRT_WRITE ? OBD_BRW_WRITE : OBD_BRW_READ;
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oap->oap_page_off = opg->ops_from;
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oap->oap_count = opg->ops_to - opg->ops_from;
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oap->oap_brw_flags = brw_flags | OBD_BRW_SYNC;
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if (capable(CFS_CAP_SYS_RESOURCE)) {
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oap->oap_brw_flags |= OBD_BRW_NOQUOTA;
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oap->oap_cmd |= OBD_BRW_NOQUOTA;
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}
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opg->ops_submit_time = cfs_time_current();
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osc_page_transfer_get(opg, "transfer\0imm");
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osc_page_transfer_add(env, opg, crt);
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}
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/* --------------- LRU page management ------------------ */
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/* OSC is a natural place to manage LRU pages as applications are specialized
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* to write OSC by OSC. Ideally, if one OSC is used more frequently it should
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* occupy more LRU slots. On the other hand, we should avoid using up all LRU
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* slots (client_obd::cl_lru_left) otherwise process has to be put into sleep
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* for free LRU slots - this will be very bad so the algorithm requires each
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* OSC to free slots voluntarily to maintain a reasonable number of free slots
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* at any time.
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*/
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static DECLARE_WAIT_QUEUE_HEAD(osc_lru_waitq);
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/**
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* LRU pages are freed in batch mode. OSC should at least free this
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* number of pages to avoid running out of LRU slots.
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*/
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static inline int lru_shrink_min(struct client_obd *cli)
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{
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return cli->cl_max_pages_per_rpc * 2;
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}
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/**
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* free this number at most otherwise it will take too long time to finish.
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*/
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static inline int lru_shrink_max(struct client_obd *cli)
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{
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return cli->cl_max_pages_per_rpc * cli->cl_max_rpcs_in_flight;
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}
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/**
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* Check if we can free LRU slots from this OSC. If there exists LRU waiters,
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* we should free slots aggressively. In this way, slots are freed in a steady
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* step to maintain fairness among OSCs.
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*
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* Return how many LRU pages should be freed.
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*/
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static int osc_cache_too_much(struct client_obd *cli)
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{
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struct cl_client_cache *cache = cli->cl_cache;
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long pages = atomic_long_read(&cli->cl_lru_in_list);
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unsigned long budget;
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budget = cache->ccc_lru_max / (atomic_read(&cache->ccc_users) - 2);
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/* if it's going to run out LRU slots, we should free some, but not
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* too much to maintain fairness among OSCs.
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*/
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if (atomic_long_read(cli->cl_lru_left) < cache->ccc_lru_max >> 2) {
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if (pages >= budget)
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return lru_shrink_max(cli);
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else if (pages >= budget / 2)
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return lru_shrink_min(cli);
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} else {
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time64_t duration = ktime_get_real_seconds();
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long timediff;
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/* knock out pages by duration of no IO activity */
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duration -= cli->cl_lru_last_used;
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/*
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* The difference shouldn't be more than 70 years
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* so we can safely case to a long. Round to
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* approximately 1 minute.
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*/
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timediff = (long)(duration >> 6);
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if (timediff > 0 && pages >= budget / timediff)
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return lru_shrink_min(cli);
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}
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return 0;
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}
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int lru_queue_work(const struct lu_env *env, void *data)
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{
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struct client_obd *cli = data;
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int count;
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CDEBUG(D_CACHE, "%s: run LRU work for client obd\n", cli_name(cli));
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count = osc_cache_too_much(cli);
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if (count > 0) {
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int rc = osc_lru_shrink(env, cli, count, false);
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CDEBUG(D_CACHE, "%s: shrank %d/%d pages from client obd\n",
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cli_name(cli), rc, count);
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if (rc >= count) {
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CDEBUG(D_CACHE, "%s: queue again\n", cli_name(cli));
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ptlrpcd_queue_work(cli->cl_lru_work);
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}
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}
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return 0;
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}
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void osc_lru_add_batch(struct client_obd *cli, struct list_head *plist)
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{
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LIST_HEAD(lru);
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struct osc_async_page *oap;
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long npages = 0;
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list_for_each_entry(oap, plist, oap_pending_item) {
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struct osc_page *opg = oap2osc_page(oap);
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if (!opg->ops_in_lru)
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continue;
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++npages;
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LASSERT(list_empty(&opg->ops_lru));
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list_add(&opg->ops_lru, &lru);
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}
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if (npages > 0) {
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spin_lock(&cli->cl_lru_list_lock);
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list_splice_tail(&lru, &cli->cl_lru_list);
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atomic_long_sub(npages, &cli->cl_lru_busy);
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atomic_long_add(npages, &cli->cl_lru_in_list);
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cli->cl_lru_last_used = ktime_get_real_seconds();
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spin_unlock(&cli->cl_lru_list_lock);
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if (waitqueue_active(&osc_lru_waitq))
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(void)ptlrpcd_queue_work(cli->cl_lru_work);
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}
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}
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static void __osc_lru_del(struct client_obd *cli, struct osc_page *opg)
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{
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LASSERT(atomic_long_read(&cli->cl_lru_in_list) > 0);
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list_del_init(&opg->ops_lru);
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atomic_long_dec(&cli->cl_lru_in_list);
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}
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/**
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* Page is being destroyed. The page may be not in LRU list, if the transfer
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* has never finished(error occurred).
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*/
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static void osc_lru_del(struct client_obd *cli, struct osc_page *opg)
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{
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if (opg->ops_in_lru) {
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spin_lock(&cli->cl_lru_list_lock);
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if (!list_empty(&opg->ops_lru)) {
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__osc_lru_del(cli, opg);
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} else {
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LASSERT(atomic_long_read(&cli->cl_lru_busy) > 0);
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atomic_long_dec(&cli->cl_lru_busy);
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}
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spin_unlock(&cli->cl_lru_list_lock);
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atomic_long_inc(cli->cl_lru_left);
|
|
/* this is a great place to release more LRU pages if
|
|
* this osc occupies too many LRU pages and kernel is
|
|
* stealing one of them.
|
|
*/
|
|
if (osc_cache_too_much(cli)) {
|
|
CDEBUG(D_CACHE, "%s: queue LRU work\n", cli_name(cli));
|
|
(void)ptlrpcd_queue_work(cli->cl_lru_work);
|
|
}
|
|
wake_up(&osc_lru_waitq);
|
|
} else {
|
|
LASSERT(list_empty(&opg->ops_lru));
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Delete page from LRUlist for redirty.
|
|
*/
|
|
static void osc_lru_use(struct client_obd *cli, struct osc_page *opg)
|
|
{
|
|
/* If page is being transferred for the first time,
|
|
* ops_lru should be empty
|
|
*/
|
|
if (opg->ops_in_lru && !list_empty(&opg->ops_lru)) {
|
|
spin_lock(&cli->cl_lru_list_lock);
|
|
__osc_lru_del(cli, opg);
|
|
spin_unlock(&cli->cl_lru_list_lock);
|
|
atomic_long_inc(&cli->cl_lru_busy);
|
|
}
|
|
}
|
|
|
|
static void discard_pagevec(const struct lu_env *env, struct cl_io *io,
|
|
struct cl_page **pvec, int max_index)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < max_index; i++) {
|
|
struct cl_page *page = pvec[i];
|
|
|
|
LASSERT(cl_page_is_owned(page, io));
|
|
cl_page_delete(env, page);
|
|
cl_page_discard(env, io, page);
|
|
cl_page_disown(env, io, page);
|
|
cl_page_put(env, page);
|
|
|
|
pvec[i] = NULL;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Check if a cl_page can be released, i.e, it's not being used.
|
|
*
|
|
* If unstable account is turned on, bulk transfer may hold one refcount
|
|
* for recovery so we need to check vmpage refcount as well; otherwise,
|
|
* even we can destroy cl_page but the corresponding vmpage can't be reused.
|
|
*/
|
|
static inline bool lru_page_busy(struct client_obd *cli, struct cl_page *page)
|
|
{
|
|
if (cl_page_in_use_noref(page))
|
|
return true;
|
|
|
|
if (cli->cl_cache->ccc_unstable_check) {
|
|
struct page *vmpage = cl_page_vmpage(page);
|
|
|
|
/* vmpage have two known users: cl_page and VM page cache */
|
|
if (page_count(vmpage) - page_mapcount(vmpage) > 2)
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Drop @target of pages from LRU at most.
|
|
*/
|
|
long osc_lru_shrink(const struct lu_env *env, struct client_obd *cli,
|
|
long target, bool force)
|
|
{
|
|
struct cl_io *io;
|
|
struct cl_object *clobj = NULL;
|
|
struct cl_page **pvec;
|
|
struct osc_page *opg;
|
|
int maxscan = 0;
|
|
long count = 0;
|
|
int index = 0;
|
|
int rc = 0;
|
|
|
|
LASSERT(atomic_long_read(&cli->cl_lru_in_list) >= 0);
|
|
if (atomic_long_read(&cli->cl_lru_in_list) == 0 || target <= 0)
|
|
return 0;
|
|
|
|
CDEBUG(D_CACHE, "%s: shrinkers: %d, force: %d\n",
|
|
cli_name(cli), atomic_read(&cli->cl_lru_shrinkers), force);
|
|
if (!force) {
|
|
if (atomic_read(&cli->cl_lru_shrinkers) > 0)
|
|
return -EBUSY;
|
|
|
|
if (atomic_inc_return(&cli->cl_lru_shrinkers) > 1) {
|
|
atomic_dec(&cli->cl_lru_shrinkers);
|
|
return -EBUSY;
|
|
}
|
|
} else {
|
|
atomic_inc(&cli->cl_lru_shrinkers);
|
|
}
|
|
|
|
pvec = (struct cl_page **)osc_env_info(env)->oti_pvec;
|
|
io = &osc_env_info(env)->oti_io;
|
|
|
|
spin_lock(&cli->cl_lru_list_lock);
|
|
if (force)
|
|
cli->cl_lru_reclaim++;
|
|
maxscan = min(target << 1, atomic_long_read(&cli->cl_lru_in_list));
|
|
while (!list_empty(&cli->cl_lru_list)) {
|
|
struct cl_page *page;
|
|
bool will_free = false;
|
|
|
|
if (!force && atomic_read(&cli->cl_lru_shrinkers) > 1)
|
|
break;
|
|
|
|
if (--maxscan < 0)
|
|
break;
|
|
|
|
opg = list_entry(cli->cl_lru_list.next, struct osc_page,
|
|
ops_lru);
|
|
page = opg->ops_cl.cpl_page;
|
|
if (lru_page_busy(cli, page)) {
|
|
list_move_tail(&opg->ops_lru, &cli->cl_lru_list);
|
|
continue;
|
|
}
|
|
|
|
LASSERT(page->cp_obj);
|
|
if (clobj != page->cp_obj) {
|
|
struct cl_object *tmp = page->cp_obj;
|
|
|
|
cl_object_get(tmp);
|
|
spin_unlock(&cli->cl_lru_list_lock);
|
|
|
|
if (clobj) {
|
|
discard_pagevec(env, io, pvec, index);
|
|
index = 0;
|
|
|
|
cl_io_fini(env, io);
|
|
cl_object_put(env, clobj);
|
|
clobj = NULL;
|
|
}
|
|
|
|
clobj = tmp;
|
|
io->ci_obj = clobj;
|
|
io->ci_ignore_layout = 1;
|
|
rc = cl_io_init(env, io, CIT_MISC, clobj);
|
|
|
|
spin_lock(&cli->cl_lru_list_lock);
|
|
|
|
if (rc != 0)
|
|
break;
|
|
|
|
++maxscan;
|
|
continue;
|
|
}
|
|
|
|
if (cl_page_own_try(env, io, page) == 0) {
|
|
if (!lru_page_busy(cli, page)) {
|
|
/* remove it from lru list earlier to avoid
|
|
* lock contention
|
|
*/
|
|
__osc_lru_del(cli, opg);
|
|
opg->ops_in_lru = 0; /* will be discarded */
|
|
|
|
cl_page_get(page);
|
|
will_free = true;
|
|
} else {
|
|
cl_page_disown(env, io, page);
|
|
}
|
|
}
|
|
|
|
if (!will_free) {
|
|
list_move_tail(&opg->ops_lru, &cli->cl_lru_list);
|
|
continue;
|
|
}
|
|
|
|
/* Don't discard and free the page with cl_lru_list held */
|
|
pvec[index++] = page;
|
|
if (unlikely(index == OTI_PVEC_SIZE)) {
|
|
spin_unlock(&cli->cl_lru_list_lock);
|
|
discard_pagevec(env, io, pvec, index);
|
|
index = 0;
|
|
|
|
spin_lock(&cli->cl_lru_list_lock);
|
|
}
|
|
|
|
if (++count >= target)
|
|
break;
|
|
}
|
|
spin_unlock(&cli->cl_lru_list_lock);
|
|
|
|
if (clobj) {
|
|
discard_pagevec(env, io, pvec, index);
|
|
|
|
cl_io_fini(env, io);
|
|
cl_object_put(env, clobj);
|
|
}
|
|
|
|
atomic_dec(&cli->cl_lru_shrinkers);
|
|
if (count > 0) {
|
|
atomic_long_add(count, cli->cl_lru_left);
|
|
wake_up_all(&osc_lru_waitq);
|
|
}
|
|
return count > 0 ? count : rc;
|
|
}
|
|
|
|
/**
|
|
* Reclaim LRU pages by an IO thread. The caller wants to reclaim at least
|
|
* \@npages of LRU slots. For performance consideration, it's better to drop
|
|
* LRU pages in batch. Therefore, the actual number is adjusted at least
|
|
* max_pages_per_rpc.
|
|
*/
|
|
long osc_lru_reclaim(struct client_obd *cli, unsigned long npages)
|
|
{
|
|
struct lu_env *env;
|
|
struct cl_client_cache *cache = cli->cl_cache;
|
|
int max_scans;
|
|
int refcheck;
|
|
long rc = 0;
|
|
|
|
LASSERT(cache);
|
|
|
|
env = cl_env_get(&refcheck);
|
|
if (IS_ERR(env))
|
|
return 0;
|
|
|
|
npages = max_t(int, npages, cli->cl_max_pages_per_rpc);
|
|
CDEBUG(D_CACHE, "%s: start to reclaim %ld pages from LRU\n",
|
|
cli_name(cli), npages);
|
|
rc = osc_lru_shrink(env, cli, npages, true);
|
|
if (rc >= npages) {
|
|
CDEBUG(D_CACHE, "%s: reclaimed %ld/%ld pages from LRU\n",
|
|
cli_name(cli), rc, npages);
|
|
if (osc_cache_too_much(cli) > 0)
|
|
ptlrpcd_queue_work(cli->cl_lru_work);
|
|
goto out;
|
|
} else if (rc > 0) {
|
|
npages -= rc;
|
|
}
|
|
|
|
CDEBUG(D_CACHE, "%s: cli %p no free slots, pages: %ld/%ld, want: %ld\n",
|
|
cli_name(cli), cli, atomic_long_read(&cli->cl_lru_in_list),
|
|
atomic_long_read(&cli->cl_lru_busy), npages);
|
|
|
|
/* Reclaim LRU slots from other client_obd as it can't free enough
|
|
* from its own. This should rarely happen.
|
|
*/
|
|
spin_lock(&cache->ccc_lru_lock);
|
|
LASSERT(!list_empty(&cache->ccc_lru));
|
|
|
|
cache->ccc_lru_shrinkers++;
|
|
list_move_tail(&cli->cl_lru_osc, &cache->ccc_lru);
|
|
|
|
max_scans = atomic_read(&cache->ccc_users) - 2;
|
|
while (--max_scans > 0 && !list_empty(&cache->ccc_lru)) {
|
|
cli = list_entry(cache->ccc_lru.next, struct client_obd,
|
|
cl_lru_osc);
|
|
|
|
CDEBUG(D_CACHE, "%s: cli %p LRU pages: %ld, busy: %ld.\n",
|
|
cli_name(cli), cli,
|
|
atomic_long_read(&cli->cl_lru_in_list),
|
|
atomic_long_read(&cli->cl_lru_busy));
|
|
|
|
list_move_tail(&cli->cl_lru_osc, &cache->ccc_lru);
|
|
if (osc_cache_too_much(cli) > 0) {
|
|
spin_unlock(&cache->ccc_lru_lock);
|
|
|
|
rc = osc_lru_shrink(env, cli, npages, true);
|
|
spin_lock(&cache->ccc_lru_lock);
|
|
if (rc >= npages)
|
|
break;
|
|
if (rc > 0)
|
|
npages -= rc;
|
|
}
|
|
}
|
|
spin_unlock(&cache->ccc_lru_lock);
|
|
|
|
out:
|
|
cl_env_put(env, &refcheck);
|
|
CDEBUG(D_CACHE, "%s: cli %p freed %ld pages.\n",
|
|
cli_name(cli), cli, rc);
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* osc_lru_reserve() is called to reserve an LRU slot for a cl_page.
|
|
*
|
|
* Usually the LRU slots are reserved in osc_io_iter_rw_init().
|
|
* Only in the case that the LRU slots are in extreme shortage, it should
|
|
* have reserved enough slots for an IO.
|
|
*/
|
|
static int osc_lru_reserve(const struct lu_env *env, struct osc_object *obj,
|
|
struct osc_page *opg)
|
|
{
|
|
struct l_wait_info lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);
|
|
struct osc_io *oio = osc_env_io(env);
|
|
struct client_obd *cli = osc_cli(obj);
|
|
int rc = 0;
|
|
|
|
if (!cli->cl_cache) /* shall not be in LRU */
|
|
return 0;
|
|
|
|
if (oio->oi_lru_reserved > 0) {
|
|
--oio->oi_lru_reserved;
|
|
goto out;
|
|
}
|
|
|
|
LASSERT(atomic_long_read(cli->cl_lru_left) >= 0);
|
|
while (!atomic_long_add_unless(cli->cl_lru_left, -1, 0)) {
|
|
/* run out of LRU spaces, try to drop some by itself */
|
|
rc = osc_lru_reclaim(cli, 1);
|
|
if (rc < 0)
|
|
break;
|
|
if (rc > 0)
|
|
continue;
|
|
|
|
cond_resched();
|
|
|
|
rc = l_wait_event(osc_lru_waitq,
|
|
atomic_long_read(cli->cl_lru_left) > 0,
|
|
&lwi);
|
|
|
|
if (rc < 0)
|
|
break;
|
|
}
|
|
|
|
out:
|
|
if (rc >= 0) {
|
|
atomic_long_inc(&cli->cl_lru_busy);
|
|
opg->ops_in_lru = 1;
|
|
rc = 0;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* Atomic operations are expensive. We accumulate the accounting for the
|
|
* same page pgdat to get better performance.
|
|
* In practice this can work pretty good because the pages in the same RPC
|
|
* are likely from the same page zone.
|
|
*/
|
|
static inline void unstable_page_accounting(struct ptlrpc_bulk_desc *desc,
|
|
int factor)
|
|
{
|
|
int page_count = desc->bd_iov_count;
|
|
pg_data_t *last = NULL;
|
|
int count = 0;
|
|
int i;
|
|
|
|
LASSERT(ptlrpc_is_bulk_desc_kiov(desc->bd_type));
|
|
|
|
for (i = 0; i < page_count; i++) {
|
|
pg_data_t *pgdat = page_pgdat(BD_GET_KIOV(desc, i).bv_page);
|
|
|
|
if (likely(pgdat == last)) {
|
|
++count;
|
|
continue;
|
|
}
|
|
|
|
if (count > 0) {
|
|
mod_node_page_state(pgdat, NR_UNSTABLE_NFS,
|
|
factor * count);
|
|
count = 0;
|
|
}
|
|
last = pgdat;
|
|
++count;
|
|
}
|
|
if (count > 0)
|
|
mod_node_page_state(last, NR_UNSTABLE_NFS, factor * count);
|
|
}
|
|
|
|
static inline void add_unstable_page_accounting(struct ptlrpc_bulk_desc *desc)
|
|
{
|
|
unstable_page_accounting(desc, 1);
|
|
}
|
|
|
|
static inline void dec_unstable_page_accounting(struct ptlrpc_bulk_desc *desc)
|
|
{
|
|
unstable_page_accounting(desc, -1);
|
|
}
|
|
|
|
/**
|
|
* Performs "unstable" page accounting. This function balances the
|
|
* increment operations performed in osc_inc_unstable_pages. It is
|
|
* registered as the RPC request callback, and is executed when the
|
|
* bulk RPC is committed on the server. Thus at this point, the pages
|
|
* involved in the bulk transfer are no longer considered unstable.
|
|
*
|
|
* If this function is called, the request should have been committed
|
|
* or req:rq_unstable must have been set; it implies that the unstable
|
|
* statistic have been added.
|
|
*/
|
|
void osc_dec_unstable_pages(struct ptlrpc_request *req)
|
|
{
|
|
struct client_obd *cli = &req->rq_import->imp_obd->u.cli;
|
|
struct ptlrpc_bulk_desc *desc = req->rq_bulk;
|
|
int page_count = desc->bd_iov_count;
|
|
long unstable_count;
|
|
|
|
LASSERT(page_count >= 0);
|
|
dec_unstable_page_accounting(desc);
|
|
|
|
unstable_count = atomic_long_sub_return(page_count,
|
|
&cli->cl_unstable_count);
|
|
LASSERT(unstable_count >= 0);
|
|
|
|
unstable_count = atomic_long_sub_return(page_count,
|
|
&cli->cl_cache->ccc_unstable_nr);
|
|
LASSERT(unstable_count >= 0);
|
|
if (!unstable_count)
|
|
wake_up_all(&cli->cl_cache->ccc_unstable_waitq);
|
|
|
|
if (waitqueue_active(&osc_lru_waitq))
|
|
(void)ptlrpcd_queue_work(cli->cl_lru_work);
|
|
}
|
|
|
|
/**
|
|
* "unstable" page accounting. See: osc_dec_unstable_pages.
|
|
*/
|
|
void osc_inc_unstable_pages(struct ptlrpc_request *req)
|
|
{
|
|
struct client_obd *cli = &req->rq_import->imp_obd->u.cli;
|
|
struct ptlrpc_bulk_desc *desc = req->rq_bulk;
|
|
long page_count = desc->bd_iov_count;
|
|
|
|
/* No unstable page tracking */
|
|
if (!cli->cl_cache || !cli->cl_cache->ccc_unstable_check)
|
|
return;
|
|
|
|
add_unstable_page_accounting(desc);
|
|
atomic_long_add(page_count, &cli->cl_unstable_count);
|
|
atomic_long_add(page_count, &cli->cl_cache->ccc_unstable_nr);
|
|
|
|
/*
|
|
* If the request has already been committed (i.e. brw_commit
|
|
* called via rq_commit_cb), we need to undo the unstable page
|
|
* increments we just performed because rq_commit_cb wont be
|
|
* called again.
|
|
*/
|
|
spin_lock(&req->rq_lock);
|
|
if (unlikely(req->rq_committed)) {
|
|
spin_unlock(&req->rq_lock);
|
|
|
|
osc_dec_unstable_pages(req);
|
|
} else {
|
|
req->rq_unstable = 1;
|
|
spin_unlock(&req->rq_lock);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Check if it piggybacks SOFT_SYNC flag to OST from this OSC.
|
|
* This function will be called by every BRW RPC so it's critical
|
|
* to make this function fast.
|
|
*/
|
|
bool osc_over_unstable_soft_limit(struct client_obd *cli)
|
|
{
|
|
long unstable_nr, osc_unstable_count;
|
|
|
|
/* Can't check cli->cl_unstable_count, therefore, no soft limit */
|
|
if (!cli->cl_cache || !cli->cl_cache->ccc_unstable_check)
|
|
return false;
|
|
|
|
osc_unstable_count = atomic_long_read(&cli->cl_unstable_count);
|
|
unstable_nr = atomic_long_read(&cli->cl_cache->ccc_unstable_nr);
|
|
|
|
CDEBUG(D_CACHE,
|
|
"%s: cli: %p unstable pages: %lu, osc unstable pages: %lu\n",
|
|
cli_name(cli), cli, unstable_nr, osc_unstable_count);
|
|
|
|
/*
|
|
* If the LRU slots are in shortage - 25% remaining AND this OSC
|
|
* has one full RPC window of unstable pages, it's a good chance
|
|
* to piggyback a SOFT_SYNC flag.
|
|
* Please notice that the OST won't take immediate response for the
|
|
* SOFT_SYNC request so active OSCs will have more chance to carry
|
|
* the flag, this is reasonable.
|
|
*/
|
|
return unstable_nr > cli->cl_cache->ccc_lru_max >> 2 &&
|
|
osc_unstable_count > cli->cl_max_pages_per_rpc *
|
|
cli->cl_max_rpcs_in_flight;
|
|
}
|
|
|
|
/**
|
|
* Return how many LRU pages in the cache of all OSC devices
|
|
*
|
|
* Return: return # of cached LRU pages times reclaimation tendency
|
|
* SHRINK_STOP if it cannot do any scanning in this time
|
|
*/
|
|
unsigned long osc_cache_shrink_count(struct shrinker *sk,
|
|
struct shrink_control *sc)
|
|
{
|
|
struct client_obd *cli;
|
|
unsigned long cached = 0;
|
|
|
|
spin_lock(&osc_shrink_lock);
|
|
list_for_each_entry(cli, &osc_shrink_list, cl_shrink_list)
|
|
cached += atomic_long_read(&cli->cl_lru_in_list);
|
|
spin_unlock(&osc_shrink_lock);
|
|
|
|
return (cached * sysctl_vfs_cache_pressure) / 100;
|
|
}
|
|
|
|
/**
|
|
* Scan and try to reclaim sc->nr_to_scan cached LRU pages
|
|
*
|
|
* Return: number of cached LRU pages reclaimed
|
|
* SHRINK_STOP if it cannot do any scanning in this time
|
|
*
|
|
* Linux kernel will loop calling this shrinker scan routine with
|
|
* sc->nr_to_scan = SHRINK_BATCH(128 for now) until kernel got enough memory.
|
|
*
|
|
* If sc->nr_to_scan is 0, the VM is querying the cache size, we don't need
|
|
* to scan and try to reclaim LRU pages, just return 0 and
|
|
* osc_cache_shrink_count() will report the LRU page number.
|
|
*/
|
|
unsigned long osc_cache_shrink_scan(struct shrinker *sk,
|
|
struct shrink_control *sc)
|
|
{
|
|
struct client_obd *stop_anchor = NULL;
|
|
struct client_obd *cli;
|
|
struct lu_env *env;
|
|
long shrank = 0;
|
|
int refcheck;
|
|
int rc;
|
|
|
|
if (!sc->nr_to_scan)
|
|
return 0;
|
|
|
|
if (!(sc->gfp_mask & __GFP_FS))
|
|
return SHRINK_STOP;
|
|
|
|
env = cl_env_get(&refcheck);
|
|
if (IS_ERR(env))
|
|
return SHRINK_STOP;
|
|
|
|
spin_lock(&osc_shrink_lock);
|
|
while (!list_empty(&osc_shrink_list)) {
|
|
cli = list_entry(osc_shrink_list.next, struct client_obd,
|
|
cl_shrink_list);
|
|
|
|
if (!stop_anchor)
|
|
stop_anchor = cli;
|
|
else if (cli == stop_anchor)
|
|
break;
|
|
|
|
list_move_tail(&cli->cl_shrink_list, &osc_shrink_list);
|
|
spin_unlock(&osc_shrink_lock);
|
|
|
|
/* shrink no more than max_pages_per_rpc for an OSC */
|
|
rc = osc_lru_shrink(env, cli, (sc->nr_to_scan - shrank) >
|
|
cli->cl_max_pages_per_rpc ?
|
|
cli->cl_max_pages_per_rpc :
|
|
sc->nr_to_scan - shrank, true);
|
|
if (rc > 0)
|
|
shrank += rc;
|
|
|
|
if (shrank >= sc->nr_to_scan)
|
|
goto out;
|
|
|
|
spin_lock(&osc_shrink_lock);
|
|
}
|
|
spin_unlock(&osc_shrink_lock);
|
|
|
|
out:
|
|
cl_env_put(env, &refcheck);
|
|
|
|
return shrank;
|
|
}
|
|
|
|
/** @} osc */
|