powerpc/pseries: Add collaborative memory manager
Adds a collaborative memory manager, which acts as a simple balloon driver for System p machines that support cooperative memory overcommitment (CMO). Adds a platform configuration option for CMO called PPC_SMLPAR. Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Brian King
Benjamin Herrenschmidt
parent
86630a3232
commit
84af458bb2
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@ -40,3 +40,26 @@ config PPC_PSERIES_DEBUG
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depends on PPC_PSERIES && PPC_EARLY_DEBUG
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bool "Enable extra debug logging in platforms/pseries"
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default y
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config PPC_SMLPAR
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bool "Support for shared-memory logical partitions"
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depends on PPC_PSERIES
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select LPARCFG
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default n
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help
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Select this option to enable shared memory partition support.
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With this option a system running in an LPAR can be given more
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memory than physically available and will allow firmware to
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balance memory across many LPARs.
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config CMM
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tristate "Collaborative memory management"
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depends on PPC_SMLPAR
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default y
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help
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Select this option, if you want to enable the kernel interface
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to reduce the memory size of the system. This is accomplished
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by allocating pages of memory and put them "on hold". This only
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makes sense for a system running in an LPAR where the unused pages
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will be reused for other LPARs. The interface allows firmware to
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balance memory across many LPARs.
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@ -24,3 +24,4 @@ obj-$(CONFIG_HVC_CONSOLE) += hvconsole.o
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obj-$(CONFIG_HVCS) += hvcserver.o
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obj-$(CONFIG_HCALL_STATS) += hvCall_inst.o
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obj-$(CONFIG_PHYP_DUMP) += phyp_dump.o
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obj-$(CONFIG_CMM) += cmm.o
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@ -0,0 +1,468 @@
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/*
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* Collaborative memory management interface.
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*
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* Copyright (C) 2008 IBM Corporation
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* Author(s): Brian King (brking@linux.vnet.ibm.com),
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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 as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <linux/ctype.h>
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#include <linux/delay.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/init.h>
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#include <linux/kthread.h>
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#include <linux/module.h>
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#include <linux/oom.h>
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#include <linux/sched.h>
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#include <linux/stringify.h>
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#include <linux/swap.h>
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#include <linux/sysdev.h>
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#include <asm/firmware.h>
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#include <asm/hvcall.h>
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#include <asm/mmu.h>
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#include <asm/pgalloc.h>
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#include <asm/uaccess.h>
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#include "plpar_wrappers.h"
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#define CMM_DRIVER_VERSION "1.0.0"
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#define CMM_DEFAULT_DELAY 1
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#define CMM_DEBUG 0
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#define CMM_DISABLE 0
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#define CMM_OOM_KB 1024
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#define CMM_MIN_MEM_MB 256
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#define KB2PAGES(_p) ((_p)>>(PAGE_SHIFT-10))
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#define PAGES2KB(_p) ((_p)<<(PAGE_SHIFT-10))
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static unsigned int delay = CMM_DEFAULT_DELAY;
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static unsigned int oom_kb = CMM_OOM_KB;
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static unsigned int cmm_debug = CMM_DEBUG;
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static unsigned int cmm_disabled = CMM_DISABLE;
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static unsigned long min_mem_mb = CMM_MIN_MEM_MB;
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static struct sys_device cmm_sysdev;
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MODULE_AUTHOR("Brian King <brking@linux.vnet.ibm.com>");
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MODULE_DESCRIPTION("IBM System p Collaborative Memory Manager");
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MODULE_LICENSE("GPL");
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MODULE_VERSION(CMM_DRIVER_VERSION);
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module_param_named(delay, delay, uint, S_IRUGO | S_IWUSR);
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MODULE_PARM_DESC(delay, "Delay (in seconds) between polls to query hypervisor paging requests. "
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"[Default=" __stringify(CMM_DEFAULT_DELAY) "]");
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module_param_named(oom_kb, oom_kb, uint, S_IRUGO | S_IWUSR);
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MODULE_PARM_DESC(oom_kb, "Amount of memory in kb to free on OOM. "
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"[Default=" __stringify(CMM_OOM_KB) "]");
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module_param_named(min_mem_mb, min_mem_mb, ulong, S_IRUGO | S_IWUSR);
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MODULE_PARM_DESC(min_mem_mb, "Minimum amount of memory (in MB) to not balloon. "
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"[Default=" __stringify(CMM_MIN_MEM_MB) "]");
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module_param_named(debug, cmm_debug, uint, S_IRUGO | S_IWUSR);
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MODULE_PARM_DESC(debug, "Enable module debugging logging. Set to 1 to enable. "
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"[Default=" __stringify(CMM_DEBUG) "]");
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#define CMM_NR_PAGES ((PAGE_SIZE - sizeof(void *) - sizeof(unsigned long)) / sizeof(unsigned long))
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#define cmm_dbg(...) if (cmm_debug) { printk(KERN_INFO "cmm: "__VA_ARGS__); }
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struct cmm_page_array {
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struct cmm_page_array *next;
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unsigned long index;
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unsigned long page[CMM_NR_PAGES];
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};
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static unsigned long loaned_pages;
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static unsigned long loaned_pages_target;
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static unsigned long oom_freed_pages;
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static struct cmm_page_array *cmm_page_list;
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static DEFINE_SPINLOCK(cmm_lock);
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static struct task_struct *cmm_thread_ptr;
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/**
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* cmm_alloc_pages - Allocate pages and mark them as loaned
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* @nr: number of pages to allocate
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*
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* Return value:
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* number of pages requested to be allocated which were not
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**/
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static long cmm_alloc_pages(long nr)
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{
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struct cmm_page_array *pa, *npa;
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unsigned long addr;
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long rc;
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cmm_dbg("Begin request for %ld pages\n", nr);
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while (nr) {
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addr = __get_free_page(GFP_NOIO | __GFP_NOWARN |
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__GFP_NORETRY | __GFP_NOMEMALLOC);
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if (!addr)
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break;
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spin_lock(&cmm_lock);
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pa = cmm_page_list;
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if (!pa || pa->index >= CMM_NR_PAGES) {
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/* Need a new page for the page list. */
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spin_unlock(&cmm_lock);
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npa = (struct cmm_page_array *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
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__GFP_NORETRY | __GFP_NOMEMALLOC);
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if (!npa) {
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pr_info("%s: Can not allocate new page list\n", __FUNCTION__);
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free_page(addr);
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break;
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}
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spin_lock(&cmm_lock);
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pa = cmm_page_list;
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if (!pa || pa->index >= CMM_NR_PAGES) {
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npa->next = pa;
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npa->index = 0;
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pa = npa;
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cmm_page_list = pa;
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} else
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free_page((unsigned long) npa);
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}
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if ((rc = plpar_page_set_loaned(__pa(addr)))) {
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pr_err("%s: Can not set page to loaned. rc=%ld\n", __FUNCTION__, rc);
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spin_unlock(&cmm_lock);
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free_page(addr);
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break;
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}
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pa->page[pa->index++] = addr;
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loaned_pages++;
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totalram_pages--;
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spin_unlock(&cmm_lock);
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nr--;
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}
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cmm_dbg("End request with %ld pages unfulfilled\n", nr);
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return nr;
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}
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/**
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* cmm_free_pages - Free pages and mark them as active
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* @nr: number of pages to free
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*
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* Return value:
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* number of pages requested to be freed which were not
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**/
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static long cmm_free_pages(long nr)
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{
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struct cmm_page_array *pa;
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unsigned long addr;
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cmm_dbg("Begin free of %ld pages.\n", nr);
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spin_lock(&cmm_lock);
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pa = cmm_page_list;
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while (nr) {
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if (!pa || pa->index <= 0)
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break;
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addr = pa->page[--pa->index];
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if (pa->index == 0) {
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pa = pa->next;
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free_page((unsigned long) cmm_page_list);
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cmm_page_list = pa;
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}
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plpar_page_set_active(__pa(addr));
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free_page(addr);
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loaned_pages--;
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nr--;
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totalram_pages++;
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}
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spin_unlock(&cmm_lock);
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cmm_dbg("End request with %ld pages unfulfilled\n", nr);
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return nr;
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}
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/**
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* cmm_oom_notify - OOM notifier
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* @self: notifier block struct
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* @dummy: not used
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* @parm: returned - number of pages freed
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*
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* Return value:
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* NOTIFY_OK
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**/
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static int cmm_oom_notify(struct notifier_block *self,
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unsigned long dummy, void *parm)
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{
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unsigned long *freed = parm;
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long nr = KB2PAGES(oom_kb);
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cmm_dbg("OOM processing started\n");
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nr = cmm_free_pages(nr);
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loaned_pages_target = loaned_pages;
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*freed += KB2PAGES(oom_kb) - nr;
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oom_freed_pages += KB2PAGES(oom_kb) - nr;
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cmm_dbg("OOM processing complete\n");
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return NOTIFY_OK;
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}
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/**
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* cmm_get_mpp - Read memory performance parameters
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*
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* Makes hcall to query the current page loan request from the hypervisor.
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*
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* Return value:
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* nothing
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**/
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static void cmm_get_mpp(void)
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{
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int rc;
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struct hvcall_mpp_data mpp_data;
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unsigned long active_pages_target;
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signed long page_loan_request;
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rc = h_get_mpp(&mpp_data);
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if (rc != H_SUCCESS)
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return;
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page_loan_request = div_s64((s64)mpp_data.loan_request, PAGE_SIZE);
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loaned_pages_target = page_loan_request + loaned_pages;
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if (loaned_pages_target > oom_freed_pages)
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loaned_pages_target -= oom_freed_pages;
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else
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loaned_pages_target = 0;
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active_pages_target = totalram_pages + loaned_pages - loaned_pages_target;
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if ((min_mem_mb * 1024 * 1024) > (active_pages_target * PAGE_SIZE))
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loaned_pages_target = totalram_pages + loaned_pages -
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((min_mem_mb * 1024 * 1024) / PAGE_SIZE);
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cmm_dbg("delta = %ld, loaned = %lu, target = %lu, oom = %lu, totalram = %lu\n",
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page_loan_request, loaned_pages, loaned_pages_target,
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oom_freed_pages, totalram_pages);
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}
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static struct notifier_block cmm_oom_nb = {
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.notifier_call = cmm_oom_notify
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};
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/**
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* cmm_thread - CMM task thread
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* @dummy: not used
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*
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* Return value:
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* 0
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**/
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static int cmm_thread(void *dummy)
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{
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unsigned long timeleft;
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while (1) {
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timeleft = msleep_interruptible(delay * 1000);
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if (kthread_should_stop() || timeleft) {
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loaned_pages_target = loaned_pages;
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break;
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}
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cmm_get_mpp();
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if (loaned_pages_target > loaned_pages) {
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if (cmm_alloc_pages(loaned_pages_target - loaned_pages))
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loaned_pages_target = loaned_pages;
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} else if (loaned_pages_target < loaned_pages)
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cmm_free_pages(loaned_pages - loaned_pages_target);
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}
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return 0;
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}
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#define CMM_SHOW(name, format, args...) \
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static ssize_t show_##name(struct sys_device *dev, char *buf) \
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{ \
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return sprintf(buf, format, ##args); \
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} \
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static SYSDEV_ATTR(name, S_IRUGO, show_##name, NULL)
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CMM_SHOW(loaned_kb, "%lu\n", PAGES2KB(loaned_pages));
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CMM_SHOW(loaned_target_kb, "%lu\n", PAGES2KB(loaned_pages_target));
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static ssize_t show_oom_pages(struct sys_device *dev, char *buf)
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{
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return sprintf(buf, "%lu\n", PAGES2KB(oom_freed_pages));
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}
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static ssize_t store_oom_pages(struct sys_device *dev,
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const char *buf, size_t count)
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{
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unsigned long val = simple_strtoul (buf, NULL, 10);
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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if (val != 0)
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return -EBADMSG;
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oom_freed_pages = 0;
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return count;
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}
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static SYSDEV_ATTR(oom_freed_kb, S_IWUSR| S_IRUGO,
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show_oom_pages, store_oom_pages);
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static struct sysdev_attribute *cmm_attrs[] = {
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&attr_loaned_kb,
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&attr_loaned_target_kb,
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&attr_oom_freed_kb,
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};
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static struct sysdev_class cmm_sysdev_class = {
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.name = "cmm",
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};
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/**
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* cmm_sysfs_register - Register with sysfs
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*
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* Return value:
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* 0 on success / other on failure
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**/
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static int cmm_sysfs_register(struct sys_device *sysdev)
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{
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int i, rc;
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if ((rc = sysdev_class_register(&cmm_sysdev_class)))
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return rc;
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sysdev->id = 0;
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sysdev->cls = &cmm_sysdev_class;
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if ((rc = sysdev_register(sysdev)))
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goto class_unregister;
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for (i = 0; i < ARRAY_SIZE(cmm_attrs); i++) {
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if ((rc = sysdev_create_file(sysdev, cmm_attrs[i])))
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goto fail;
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}
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return 0;
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fail:
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while (--i >= 0)
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sysdev_remove_file(sysdev, cmm_attrs[i]);
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sysdev_unregister(sysdev);
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class_unregister:
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sysdev_class_unregister(&cmm_sysdev_class);
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return rc;
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}
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/**
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* cmm_unregister_sysfs - Unregister from sysfs
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*
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**/
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static void cmm_unregister_sysfs(struct sys_device *sysdev)
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{
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int i;
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for (i = 0; i < ARRAY_SIZE(cmm_attrs); i++)
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sysdev_remove_file(sysdev, cmm_attrs[i]);
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sysdev_unregister(sysdev);
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sysdev_class_unregister(&cmm_sysdev_class);
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}
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/**
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* cmm_init - Module initialization
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*
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* Return value:
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* 0 on success / other on failure
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**/
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static int cmm_init(void)
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{
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int rc = -ENOMEM;
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if (!firmware_has_feature(FW_FEATURE_CMO))
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return -EOPNOTSUPP;
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if ((rc = register_oom_notifier(&cmm_oom_nb)) < 0)
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return rc;
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if ((rc = cmm_sysfs_register(&cmm_sysdev)))
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goto out_oom_notifier;
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if (cmm_disabled)
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return rc;
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cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
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if (IS_ERR(cmm_thread_ptr)) {
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rc = PTR_ERR(cmm_thread_ptr);
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goto out_unregister_sysfs;
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}
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return rc;
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out_unregister_sysfs:
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cmm_unregister_sysfs(&cmm_sysdev);
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out_oom_notifier:
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unregister_oom_notifier(&cmm_oom_nb);
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return rc;
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}
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/**
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* cmm_exit - Module exit
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*
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* Return value:
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* nothing
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**/
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static void cmm_exit(void)
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{
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if (cmm_thread_ptr)
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kthread_stop(cmm_thread_ptr);
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unregister_oom_notifier(&cmm_oom_nb);
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cmm_free_pages(loaned_pages);
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cmm_unregister_sysfs(&cmm_sysdev);
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}
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/**
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* cmm_set_disable - Disable/Enable CMM
|
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*
|
||||
* Return value:
|
||||
* 0 on success / other on failure
|
||||
**/
|
||||
static int cmm_set_disable(const char *val, struct kernel_param *kp)
|
||||
{
|
||||
int disable = simple_strtoul(val, NULL, 10);
|
||||
|
||||
if (disable != 0 && disable != 1)
|
||||
return -EINVAL;
|
||||
|
||||
if (disable && !cmm_disabled) {
|
||||
if (cmm_thread_ptr)
|
||||
kthread_stop(cmm_thread_ptr);
|
||||
cmm_thread_ptr = NULL;
|
||||
cmm_free_pages(loaned_pages);
|
||||
} else if (!disable && cmm_disabled) {
|
||||
cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
|
||||
if (IS_ERR(cmm_thread_ptr))
|
||||
return PTR_ERR(cmm_thread_ptr);
|
||||
}
|
||||
|
||||
cmm_disabled = disable;
|
||||
return 0;
|
||||
}
|
||||
|
||||
module_param_call(disable, cmm_set_disable, param_get_uint,
|
||||
&cmm_disabled, S_IRUGO | S_IWUSR);
|
||||
MODULE_PARM_DESC(disable, "Disable CMM. Set to 1 to disable. "
|
||||
"[Default=" __stringify(CMM_DISABLE) "]");
|
||||
|
||||
module_init(cmm_init);
|
||||
module_exit(cmm_exit);
|
||||
Reference in New Issue