Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964860AbWHWLAY (ORCPT ); Wed, 23 Aug 2006 07:00:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964859AbWHWLAX (ORCPT ); Wed, 23 Aug 2006 07:00:23 -0400 Received: from mailhub.sw.ru ([195.214.233.200]:44179 "EHLO relay.sw.ru") by vger.kernel.org with ESMTP id S964860AbWHWLAV (ORCPT ); Wed, 23 Aug 2006 07:00:21 -0400 Message-ID: <44EC35EB.1030000@sw.ru> Date: Wed, 23 Aug 2006 15:03:07 +0400 From: Kirill Korotaev User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.13) Gecko/20060417 X-Accept-Language: en-us, en, ru MIME-Version: 1.0 To: Andrew Morton CC: Linux Kernel Mailing List , Alan Cox , Christoph Hellwig , Pavel Emelianov , Andrey Savochkin , devel@openvz.org, Rik van Riel , Andi Kleen , Greg KH , Oleg Nesterov , Matt Helsley , Rohit Seth , Chandra Seetharaman Subject: [PATCH 2/6] BC: beancounters core (API) References: <44EC31FB.2050002@sw.ru> In-Reply-To: <44EC31FB.2050002@sw.ru> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 13708 Lines: 511 Core functionality and interfaces of BC: find/create beancounter, initialization, charge/uncharge of resource, core objects' declarations. Basic structures: bc_resource_parm - resource description beancounter - set of resources, id, lock Signed-off-by: Pavel Emelianov Signed-off-by: Kirill Korotaev --- include/bc/beancounter.h | 140 ++++++++++++++++++++++ init/main.c | 4 kernel/Makefile | 1 kernel/bc/Makefile | 7 + kernel/bc/beancounter.c | 292 +++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 444 insertions(+) --- /dev/null 2006-07-18 14:52:43.075228448 +0400 +++ ./include/bc/beancounter.h 2006-08-21 13:14:01.000000000 +0400 @@ -0,0 +1,140 @@ +/* + * include/bc/beancounter.h + * + * Copyright (C) 2006 OpenVZ. SWsoft Inc + * + */ + +#ifndef _LINUX_BEANCOUNTER_H +#define _LINUX_BEANCOUNTER_H + +/* + * Resource list. + */ + +#define BC_RESOURCES 0 + +struct bc_resource_parm { + unsigned long barrier; /* A barrier over which resource allocations + * are failed gracefully. e.g. if the amount + * of consumed memory is over the barrier + * further sbrk() or mmap() calls fail, the + * existing processes are not killed. + */ + unsigned long limit; /* hard resource limit */ + unsigned long held; /* consumed resources */ + unsigned long maxheld; /* maximum amount of consumed resources */ + unsigned long minheld; /* minumum amount of consumed resources */ + unsigned long failcnt; /* count of failed charges */ +}; + +/* + * Kernel internal part. + */ + +#ifdef __KERNEL__ + +#include +#include +#include +#include + +#define BC_MAXVALUE LONG_MAX + +/* + * Resource management structures + * Serialization issues: + * beancounter list management is protected via bc_hash_lock + * task pointers are set only for current task and only once + * refcount is managed atomically + * value and limit comparison and change are protected by per-bc spinlock + */ + +struct beancounter +{ + atomic_t bc_refcount; + spinlock_t bc_lock; + uid_t bc_id; + struct hlist_node hash; + + /* resources statistics and settings */ + struct bc_resource_parm bc_parms[BC_RESOURCES]; +}; + +enum severity { BC_BARRIER, BC_LIMIT, BC_FORCE }; + +/* Flags passed to beancounter_findcreate() */ +#define BC_ALLOC 0x01 /* May allocate new one */ +#define BC_ALLOC_ATOMIC 0x02 /* Allocate with GFP_ATOMIC */ + +#define BC_HASH_SIZE 256 + +#ifdef CONFIG_BEANCOUNTERS +extern struct hlist_head bc_hash[]; +extern spinlock_t bc_hash_lock; + +/* + * This function tunes minheld and maxheld values for a given + * resource when held value changes + */ +static inline void bc_adjust_held_minmax(struct beancounter *bc, + int resource) +{ + if (bc->bc_parms[resource].maxheld < bc->bc_parms[resource].held) + bc->bc_parms[resource].maxheld = bc->bc_parms[resource].held; + if (bc->bc_parms[resource].minheld > bc->bc_parms[resource].held) + bc->bc_parms[resource].minheld = bc->bc_parms[resource].held; +} + +void bc_print_resource_warning(struct beancounter *bc, int res, + char *str, unsigned long val, unsigned long held); +void bc_print_id(struct beancounter *bc, char *str, int size); + +int bc_charge_locked(struct beancounter *bc, + int res, unsigned long val, enum severity strict); +int bc_charge(struct beancounter *bc, + int res, unsigned long val, enum severity strict); + +void bc_uncharge_locked(struct beancounter *bc, + int res, unsigned long val); +void bc_uncharge(struct beancounter *bc, + int res, unsigned long val); + +struct beancounter *beancounter_findcreate(uid_t id, int mask); + +static inline struct beancounter *get_beancounter(struct beancounter *bc) +{ + atomic_inc(&bc->bc_refcount); + return bc; +} + +void __put_beancounter(struct beancounter *bc); +static inline void put_beancounter(struct beancounter *bc) +{ + __put_beancounter(bc); +} + +void bc_init_early(void); +void bc_init_late(void); +void bc_init_proc(void); + +extern struct beancounter init_bc; +extern const char *bc_rnames[]; + +#else /* CONFIG_BEANCOUNTERS */ + +#define beancounter_findcreate(id, f) (NULL) +#define get_beancounter(bc) (NULL) +#define put_beancounter(bc) do { } while (0) +#define bc_charge_locked(bc, r, v, s) (0) +#define bc_charge(bc, r, v) (0) +#define bc_uncharge_locked(bc, r, v) do { } while (0) +#define bc_uncharge(bc, r, v) do { } while (0) +#define bc_init_early() do { } while (0) +#define bc_init_late() do { } while (0) +#define bc_init_proc() do { } while (0) + +#endif /* CONFIG_BEANCOUNTERS */ +#endif /* __KERNEL__ */ + +#endif /* _LINUX_BEANCOUNTER_H */ --- ./init/main.c.ve1 2006-08-21 12:25:13.000000000 +0400 +++ ./init/main.c 2006-08-21 12:45:32.000000000 +0400 @@ -52,6 +52,8 @@ #include #include +#include + #include #include #include @@ -494,6 +496,7 @@ asmlinkage void __init start_kernel(void early_boot_irqs_off(); early_init_irq_lock_class(); + bc_init_early(); /* * Interrupts are still disabled. Do necessary setups, then * enable them @@ -587,6 +590,7 @@ asmlinkage void __init start_kernel(void #endif fork_init(num_physpages); proc_caches_init(); + bc_init_late(); buffer_init(); unnamed_dev_init(); key_init(); --- ./kernel/Makefile.ve1 2006-08-21 12:25:14.000000000 +0400 +++ ./kernel/Makefile 2006-08-21 12:25:27.000000000 +0400 @@ -12,6 +12,7 @@ obj-y = sched.o fork.o exec_domain.o obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-y += time/ +obj-y += bc/ obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o obj-$(CONFIG_LOCKDEP) += lockdep.o ifeq ($(CONFIG_PROC_FS),y) --- /dev/null 2006-07-18 14:52:43.075228448 +0400 +++ ./kernel/bc/Makefile 2006-08-21 12:25:27.000000000 +0400 @@ -0,0 +1,7 @@ +# +# Beancounters (BC) +# +# Copyright (C) 2006 OpenVZ. SWsoft Inc +# + +obj-$(CONFIG_BEANCOUNTERS) += beancounter.o --- /dev/null 2006-07-18 14:52:43.075228448 +0400 +++ ./kernel/bc/beancounter.c 2006-08-21 13:13:11.000000000 +0400 @@ -0,0 +1,292 @@ +/* + * kernel/bc/beancounter.c + * + * Copyright (C) 2006 OpenVZ. SWsoft Inc + * Original code by (C) 1998 Alan Cox + * 1998-2000 Andrey Savochkin + */ + +#include +#include + +#include + +static kmem_cache_t *bc_cachep; +static struct beancounter default_beancounter; + +static void init_beancounter_struct(struct beancounter *bc, uid_t id); + +struct beancounter init_bc; + +const char *bc_rnames[] = { +}; + +#define bc_hash_fun(x) ((((x) >> 8) ^ (x)) & (BC_HASH_SIZE - 1)) + +struct hlist_head bc_hash[BC_HASH_SIZE]; +spinlock_t bc_hash_lock; + +EXPORT_SYMBOL(bc_hash); +EXPORT_SYMBOL(bc_hash_lock); + +/* + * Per resource beancounting. Resources are tied to their luid. + * The resource structure itself is tagged both to the process and + * the charging resources (a socket doesn't want to have to search for + * things at irq time for example). Reference counters keep things in + * hand. + * + * The case where a user creates resource, kills all his processes and + * then starts new ones is correctly handled this way. The refcounters + * will mean the old entry is still around with resource tied to it. + */ + +struct beancounter *beancounter_findcreate(uid_t uid, int mask) +{ + struct beancounter *new_bc, *bc; + unsigned long flags; + struct hlist_head *slot; + struct hlist_node *pos; + + slot = &bc_hash[bc_hash_fun(uid)]; + new_bc = NULL; + +retry: + spin_lock_irqsave(&bc_hash_lock, flags); + hlist_for_each_entry (bc, pos, slot, hash) + if (bc->bc_id == uid) + break; + + if (pos != NULL) { + get_beancounter(bc); + spin_unlock_irqrestore(&bc_hash_lock, flags); + + if (new_bc != NULL) + kmem_cache_free(bc_cachep, new_bc); + return bc; + } + + if (!(mask & BC_ALLOC)) + goto out_unlock; + + if (new_bc != NULL) + goto out_install; + + spin_unlock_irqrestore(&bc_hash_lock, flags); + + new_bc = kmem_cache_alloc(bc_cachep, + mask & BC_ALLOC_ATOMIC ? GFP_ATOMIC : GFP_KERNEL); + if (new_bc == NULL) + goto out; + + memcpy(new_bc, &default_beancounter, sizeof(*new_bc)); + init_beancounter_struct(new_bc, uid); + goto retry; + +out_install: + hlist_add_head(&new_bc->hash, slot); +out_unlock: + spin_unlock_irqrestore(&bc_hash_lock, flags); +out: + return new_bc; +} + +void bc_print_id(struct beancounter *bc, char *str, int size) +{ + snprintf(str, size, "%u", bc->bc_id); +} + +void bc_print_resource_warning(struct beancounter *bc, int res, + char *str, unsigned long val, unsigned long held) +{ + char uid[64]; + + bc_print_id(bc, uid, sizeof(uid)); + printk(KERN_WARNING "BC %s %s warning: %s " + "(held %lu, fails %lu, val %lu)\n", + uid, bc_rnames[res], str, + (res < BC_RESOURCES ? bc->bc_parms[res].held : held), + (res < BC_RESOURCES ? bc->bc_parms[res].failcnt : 0), + val); +} + +static inline void verify_held(struct beancounter *bc) +{ + int i; + + for (i = 0; i < BC_RESOURCES; i++) + if (bc->bc_parms[i].held != 0) + bc_print_resource_warning(bc, i, + "resource is held on put", 0, 0); +} + +void __put_beancounter(struct beancounter *bc) +{ + unsigned long flags; + + /* equivalent to atomic_dec_and_lock_irqsave() */ + local_irq_save(flags); + if (likely(!atomic_dec_and_lock(&bc->bc_refcount, &bc_hash_lock))) { + local_irq_restore(flags); + if (unlikely(atomic_read(&bc->bc_refcount) < 0)) + printk(KERN_ERR "BC: Bad refcount: bc=%p, " + "luid=%d, ref=%d\n", + bc, bc->bc_id, + atomic_read(&bc->bc_refcount)); + return; + } + + BUG_ON(bc == &init_bc); + verify_held(bc); + hlist_del(&bc->hash); + spin_unlock_irqrestore(&bc_hash_lock, flags); + kmem_cache_free(bc_cachep, bc); +} + +EXPORT_SYMBOL(__put_beancounter); + +/* + * Generic resource charging stuff + */ + +/* called with bc->bc_lock held and interrupts disabled */ +int bc_charge_locked(struct beancounter *bc, int resource, unsigned long val, + enum severity strict) +{ + /* + * bc_value <= BC_MAXVALUE, value <= BC_MAXVALUE, and only one addition + * at the moment is possible so an overflow is impossible. + */ + bc->bc_parms[resource].held += val; + + switch (strict) { + case BC_BARRIER: + if (bc->bc_parms[resource].held > + bc->bc_parms[resource].barrier) + break; + /* fallthrough */ + case BC_LIMIT: + if (bc->bc_parms[resource].held > + bc->bc_parms[resource].limit) + break; + /* fallthrough */ + case BC_FORCE: + bc_adjust_held_minmax(bc, resource); + return 0; + default: + BUG(); + } + + bc->bc_parms[resource].failcnt++; + bc->bc_parms[resource].held -= val; + return -ENOMEM; +} +EXPORT_SYMBOL(bc_charge_locked); + +int bc_charge(struct beancounter *bc, int resource, unsigned long val, + enum severity strict) +{ + int retval; + unsigned long flags; + + BUG_ON(val > BC_MAXVALUE); + + spin_lock_irqsave(&bc->bc_lock, flags); + retval = bc_charge_locked(bc, resource, val, strict); + spin_unlock_irqrestore(&bc->bc_lock, flags); + return retval; +} +EXPORT_SYMBOL(bc_charge); + +/* called with bc->bc_lock held and interrupts disabled */ +void bc_uncharge_locked(struct beancounter *bc, int resource, unsigned long val) +{ + if (unlikely(bc->bc_parms[resource].held < val)) { + bc_print_resource_warning(bc, resource, + "uncharging too much", val, 0); + val = bc->bc_parms[resource].held; + } + + bc->bc_parms[resource].held -= val; + bc_adjust_held_minmax(bc, resource); +} +EXPORT_SYMBOL(bc_uncharge_locked); + +void bc_uncharge(struct beancounter *bc, int resource, unsigned long val) +{ + unsigned long flags; + + spin_lock_irqsave(&bc->bc_lock, flags); + bc_uncharge_locked(bc, resource, val); + spin_unlock_irqrestore(&bc->bc_lock, flags); +} +EXPORT_SYMBOL(bc_uncharge); + +/* + * Initialization + * + * struct beancounter contains + * - limits and other configuration settings + * - structural fields: lists, spinlocks and so on. + * + * Before these parts are initialized, the structure should be memset + * to 0 or copied from a known clean structure. That takes care of a lot + * of fields not initialized explicitly. + */ + +static void init_beancounter_struct(struct beancounter *bc, uid_t id) +{ + atomic_set(&bc->bc_refcount, 1); + spin_lock_init(&bc->bc_lock); + bc->bc_id = id; +} + +static void init_beancounter_nolimits(struct beancounter *bc) +{ + int k; + + for (k = 0; k < BC_RESOURCES; k++) { + bc->bc_parms[k].limit = BC_MAXVALUE; + bc->bc_parms[k].barrier = BC_MAXVALUE; + } +} + +static void init_beancounter_syslimits(struct beancounter *bc) +{ + int k; + + for (k = 0; k < BC_RESOURCES; k++) + bc->bc_parms[k].barrier = bc->bc_parms[k].limit; +} + +void __init bc_init_early(void) +{ + struct beancounter *bc; + struct hlist_head *slot; + + bc = &init_bc; + + memset(bc, 0, sizeof(*bc)); + init_beancounter_nolimits(bc); + init_beancounter_struct(bc, 0); + + spin_lock_init(&bc_hash_lock); + slot = &bc_hash[bc_hash_fun(bc->bc_id)]; + hlist_add_head(&bc->hash, slot); +} + +void __init bc_init_late(void) +{ + struct beancounter *bc; + + bc_cachep = kmem_cache_create("beancounters", + sizeof(struct beancounter), + 0, SLAB_HWCACHE_ALIGN, NULL, NULL); + if (bc_cachep == NULL) + panic("Can't create bc caches\n"); + + bc = &default_beancounter; + memset(bc, 0, sizeof(default_beancounter)); + init_beancounter_syslimits(bc); + init_beancounter_struct(bc, 0); +} - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/