Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935064Ab0GPALV (ORCPT ); Thu, 15 Jul 2010 20:11:21 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:35140 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934407Ab0GPALU (ORCPT ); Thu, 15 Jul 2010 20:11:20 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Fri, 16 Jul 2010 09:06:37 +0900 From: KAMEZAWA Hiroyuki To: Nathan Fontenot Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@ozlabs.org Subject: Re: [PATCH 1/5] v2 Split the memory_block structure Message-Id: <20100716090637.3654f91d.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <4C3F557F.3000304@austin.ibm.com> References: <4C3F53D1.3090001@austin.ibm.com> <4C3F557F.3000304@austin.ibm.com> Organization: FUJITSU Co. LTD. X-Mailer: Sylpheed 3.0.3 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 13793 Lines: 471 On Thu, 15 Jul 2010 13:37:51 -0500 Nathan Fontenot wrote: > Split the memory_block struct into a memory_block > struct to cover each sysfs directory and a new memory_block_section > struct for each memory section covered by the sysfs directory. > This change allows for creation of memory sysfs directories that > can span multiple memory sections. > > This can be beneficial in that it can reduce the number of memory > sysfs directories created at boot. This also allows different > architectures to define how many memory sections are covered by > a sysfs directory. > > Signed-off-by: Nathan Fontenot > --- > drivers/base/memory.c | 222 ++++++++++++++++++++++++++++++++++--------------- > include/linux/memory.h | 11 +- > 2 files changed, 167 insertions(+), 66 deletions(-) > > Index: linux-2.6/drivers/base/memory.c > =================================================================== > --- linux-2.6.orig/drivers/base/memory.c 2010-07-15 08:48:41.000000000 -0500 > +++ linux-2.6/drivers/base/memory.c 2010-07-15 09:55:54.000000000 -0500 > @@ -28,6 +28,14 @@ > #include > > #define MEMORY_CLASS_NAME "memory" > +#define MIN_MEMORY_BLOCK_SIZE (1 << SECTION_SIZE_BITS) > + > +static int sections_per_block; > + > +static inline int base_memory_block_id(int section_nr) > +{ > + return (section_nr / sections_per_block) * sections_per_block; > +} > > static struct sysdev_class memory_sysdev_class = { > .name = MEMORY_CLASS_NAME, > @@ -94,10 +102,9 @@ > } > > static void > -unregister_memory(struct memory_block *memory, struct mem_section *section) > +unregister_memory(struct memory_block *memory) > { > BUG_ON(memory->sysdev.cls != &memory_sysdev_class); > - BUG_ON(memory->sysdev.id != __section_nr(section)); > > /* drop the ref. we got in remove_memory_block() */ > kobject_put(&memory->sysdev.kobj); > @@ -123,13 +130,20 @@ > static ssize_t show_mem_removable(struct sys_device *dev, > struct sysdev_attribute *attr, char *buf) > { > + struct memory_block *mem; > + struct memory_block_section *mbs; > unsigned long start_pfn; > - int ret; > - struct memory_block *mem = > - container_of(dev, struct memory_block, sysdev); > + int ret = 1; > + > + mem = container_of(dev, struct memory_block, sysdev); > + mutex_lock(&mem->state_mutex); > > - start_pfn = section_nr_to_pfn(mem->phys_index); > - ret = is_mem_section_removable(start_pfn, PAGES_PER_SECTION); > + list_for_each_entry(mbs, &mem->sections, next) { > + start_pfn = section_nr_to_pfn(mbs->phys_index); > + ret &= is_mem_section_removable(start_pfn, PAGES_PER_SECTION); > + } > + > + mutex_unlock(&mem->state_mutex); Hmm, this means memory cab be offlined the while memory block section. Right ? Please write this fact in patch description... And Documentaion/memory_hotplug.txt as "From user's perspective, memory section is not a unit of memory hotplug anymore". And descirbe about a new rule. > return sprintf(buf, "%d\n", ret); > } > > @@ -182,16 +196,16 @@ > * OK to have direct references to sparsemem variables in here. > */ > static int > -memory_block_action(struct memory_block *mem, unsigned long action) > +memory_block_action(struct memory_block_section *mbs, unsigned long action) > { > int i; > unsigned long psection; > unsigned long start_pfn, start_paddr; > struct page *first_page; > int ret; > - int old_state = mem->state; > + int old_state = mbs->state; > > - psection = mem->phys_index; > + psection = mbs->phys_index; > first_page = pfn_to_page(psection << PFN_SECTION_SHIFT); > > /* > @@ -217,18 +231,18 @@ > ret = online_pages(start_pfn, PAGES_PER_SECTION); > break; > case MEM_OFFLINE: > - mem->state = MEM_GOING_OFFLINE; > + mbs->state = MEM_GOING_OFFLINE; > start_paddr = page_to_pfn(first_page) << PAGE_SHIFT; > ret = remove_memory(start_paddr, > PAGES_PER_SECTION << PAGE_SHIFT); > if (ret) { > - mem->state = old_state; > + mbs->state = old_state; > break; > } > break; > default: > WARN(1, KERN_WARNING "%s(%p, %ld) unknown action: %ld\n", > - __func__, mem, action, action); > + __func__, mbs, action, action); > ret = -EINVAL; > } > > @@ -238,19 +252,34 @@ And please check quilt's diff option. Usual patche in ML shows a function name in any changes, as @@ -241,6 +293,8 @@ static int memory_block_change_state(str Maybe "-p" option is lacked.. > static int memory_block_change_state(struct memory_block *mem, > unsigned long to_state, unsigned long from_state_req) > { > + struct memory_block_section *mbs; > int ret = 0; > + > mutex_lock(&mem->state_mutex); > > - if (mem->state != from_state_req) { > - ret = -EINVAL; > - goto out; > + list_for_each_entry(mbs, &mem->sections, next) { > + if (mbs->state != from_state_req) > + continue; > + > + ret = memory_block_action(mbs, to_state); > + if (ret) > + break; > + } > + > + if (ret) { > + list_for_each_entry(mbs, &mem->sections, next) { > + if (mbs->state == from_state_req) > + continue; > + > + if (memory_block_action(mbs, to_state)) > + printk(KERN_ERR "Could not re-enable memory " > + "section %lx\n", mbs->phys_index); Why re-enable only ? online->fail->offline never happens ? If so, please add comment at least. BTW, is it guaranteed that all sections under a block has same state after boot ? > + } > } > > - ret = memory_block_action(mem, to_state); > if (!ret) > mem->state = to_state; > > -out: > mutex_unlock(&mem->state_mutex); > return ret; > } > @@ -260,20 +289,15 @@ > struct sysdev_attribute *attr, const char *buf, size_t count) > { > struct memory_block *mem; > - unsigned int phys_section_nr; > int ret = -EINVAL; > > mem = container_of(dev, struct memory_block, sysdev); > - phys_section_nr = mem->phys_index; > - > - if (!present_section_nr(phys_section_nr)) > - goto out; > I'm sorry but I couldn't remember why this check was necessary... > if (!strncmp(buf, "online", min((int)count, 6))) > ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE); > else if(!strncmp(buf, "offline", min((int)count, 7))) > ret = memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE); > -out: > + > if (ret) > return ret; > return count; > @@ -435,39 +459,6 @@ > return 0; > } > > -static int add_memory_block(int nid, struct mem_section *section, > - unsigned long state, enum mem_add_context context) > -{ > - struct memory_block *mem = kzalloc(sizeof(*mem), GFP_KERNEL); > - unsigned long start_pfn; > - int ret = 0; > - > - if (!mem) > - return -ENOMEM; > - > - mem->phys_index = __section_nr(section); > - mem->state = state; > - mutex_init(&mem->state_mutex); > - start_pfn = section_nr_to_pfn(mem->phys_index); > - mem->phys_device = arch_get_memory_phys_device(start_pfn); > - > - ret = register_memory(mem, section); > - if (!ret) > - ret = mem_create_simple_file(mem, phys_index); > - if (!ret) > - ret = mem_create_simple_file(mem, state); > - if (!ret) > - ret = mem_create_simple_file(mem, phys_device); > - if (!ret) > - ret = mem_create_simple_file(mem, removable); > - if (!ret) { > - if (context == HOTPLUG) > - ret = register_mem_sect_under_node(mem, nid); > - } > - > - return ret; > -} > - I don't say strongly but this kind of move-code should be done in another patch. > /* > * For now, we have a linear search to go find the appropriate > * memory_block corresponding to a particular phys_index. If > @@ -482,12 +473,13 @@ > struct sys_device *sysdev; > struct memory_block *mem; > char name[sizeof(MEMORY_CLASS_NAME) + 9 + 1]; > + int block_id = base_memory_block_id(__section_nr(section)); > > /* > * This only works because we know that section == sysdev->id > * slightly redundant with sysdev_register() > */ > - sprintf(&name[0], "%s%d", MEMORY_CLASS_NAME, __section_nr(section)); > + sprintf(&name[0], "%s%d", MEMORY_CLASS_NAME, block_id); > > kobj = kset_find_obj(&memory_sysdev_class.kset, name); > if (!kobj) > @@ -499,18 +491,98 @@ > return mem; > } > > +static int add_mem_block_section(struct memory_block *mem, > + int section_nr, unsigned long state) > +{ > + struct memory_block_section *mbs; > + > + mbs = kzalloc(sizeof(*mbs), GFP_KERNEL); > + if (!mbs) > + return -ENOMEM; > + > + mbs->phys_index = section_nr; > + mbs->state = state; > + > + list_add(&mbs->next, &mem->sections); > + return 0; > +} Doesn't this "sections" need to be sorted ? Hmm. > + > +static int add_memory_block(int nid, struct mem_section *section, > + unsigned long state, enum mem_add_context context) > +{ > + struct memory_block *mem; > + int ret = 0; > + > + mem = find_memory_block(section); > + if (!mem) { > + unsigned long start_pfn; > + > + mem = kzalloc(sizeof(*mem), GFP_KERNEL); > + if (!mem) > + return -ENOMEM; > + > + mem->state = state; > + mutex_init(&mem->state_mutex); > + start_pfn = section_nr_to_pfn(__section_nr(section)); > + mem->phys_device = arch_get_memory_phys_device(start_pfn); > + INIT_LIST_HEAD(&mem->sections); > + > + mutex_lock(&mem->state_mutex); > + > + ret = register_memory(mem, section); > + if (!ret) > + ret = mem_create_simple_file(mem, phys_index); > + if (!ret) > + ret = mem_create_simple_file(mem, state); > + if (!ret) > + ret = mem_create_simple_file(mem, phys_device); > + if (!ret) > + ret = mem_create_simple_file(mem, removable); > + if (!ret) { > + if (context == HOTPLUG) > + ret = register_mem_sect_under_node(mem, nid); > + } > + } else { > + kobject_put(&mem->sysdev.kobj); > + mutex_lock(&mem->state_mutex); > + } > + > + if (!ret) > + ret = add_mem_block_section(mem, __section_nr(section), state); > + > + mutex_unlock(&mem->state_mutex); > + return ret; > +} > + > int remove_memory_block(unsigned long node_id, struct mem_section *section, > int phys_device) > { > struct memory_block *mem; > + struct memory_block_section *mbs, *tmp; > + int section_nr = __section_nr(section); > > mem = find_memory_block(section); > - unregister_mem_sect_under_nodes(mem); > - mem_remove_simple_file(mem, phys_index); > - mem_remove_simple_file(mem, state); > - mem_remove_simple_file(mem, phys_device); > - mem_remove_simple_file(mem, removable); > - unregister_memory(mem, section); > + mutex_lock(&mem->state_mutex); > + > + /* remove the specified section */ > + list_for_each_entry_safe(mbs, tmp, &mem->sections, next) { > + if (mbs->phys_index == section_nr) { > + list_del(&mbs->next); > + kfree(mbs); > + } > + } > + > + mutex_unlock(&mem->state_mutex); > + > + if (list_empty(&mem->sections)) { > + unregister_mem_sect_under_nodes(mem); > + mem_remove_simple_file(mem, phys_index); > + mem_remove_simple_file(mem, state); > + mem_remove_simple_file(mem, phys_device); > + mem_remove_simple_file(mem, removable); > + unregister_memory(mem); > + kfree(mem); > + } > > return 0; > } > @@ -532,6 +604,24 @@ > return remove_memory_block(0, section, 0); > } > > +u32 __weak memory_block_size(void) > +{ > + return MIN_MEMORY_BLOCK_SIZE; > +} > + > +static u32 get_memory_block_size(void) > +{ > + u32 blk_sz; > + > + blk_sz = memory_block_size(); > + > + /* Validate blk_sz is a power of 2 and not less than section size */ > + if ((blk_sz & (blk_sz - 1)) || (blk_sz < MIN_MEMORY_BLOCK_SIZE)) > + blk_sz = MIN_MEMORY_BLOCK_SIZE; > + > + return blk_sz; > +} > + > /* > * Initialize the sysfs support for memory devices... > */ > @@ -540,12 +630,16 @@ > unsigned int i; > int ret; > int err; > + int block_sz; > > memory_sysdev_class.kset.uevent_ops = &memory_uevent_ops; > ret = sysdev_class_register(&memory_sysdev_class); > if (ret) > goto out; > > + block_sz = get_memory_block_size(); > + sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE; > + > /* > * Create entries for memory sections that were found > * during boot and have been initialized > Index: linux-2.6/include/linux/memory.h > =================================================================== > --- linux-2.6.orig/include/linux/memory.h 2010-07-15 08:48:41.000000000 -0500 > +++ linux-2.6/include/linux/memory.h 2010-07-15 09:54:06.000000000 -0500 > @@ -19,9 +19,15 @@ > #include > #include > #include > +#include > > -struct memory_block { > +struct memory_block_section { > + unsigned long state; > unsigned long phys_index; > + struct list_head next; > +}; > + > +struct memory_block { > unsigned long state; > /* > * This serializes all state change requests. It isn't > @@ -34,6 +40,7 @@ > void *hw; /* optional pointer to fw/hw data */ > int (*phys_callback)(struct memory_block *); > struct sys_device sysdev; > + struct list_head sections; > }; > > int arch_get_memory_phys_device(unsigned long start_pfn); > @@ -113,7 +120,7 @@ > extern int remove_memory_block(unsigned long, struct mem_section *, int); > extern int memory_notify(unsigned long val, void *v); > extern int memory_isolate_notify(unsigned long val, void *v); > -extern struct memory_block *find_memory_block(unsigned long); > +extern struct memory_block *find_memory_block(struct mem_section *); > extern int memory_is_hidden(struct mem_section *); > #define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION< enum mem_add_context { BOOT, HOTPLUG }; > Okay, please go ahead. But my 1st impression is that IBM should increase ppc's SECTION_SIZE ;) Thanks, -Kame -- 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/