RE: [PATCH v7 1/8] Talitos: Support for async_tx XOR offload
On Fri, 31 Aug 2012 06:08:05 +0300, Liu Qiang-B32616 b32...@freescale.com
wrote:
-Original Message-
From: Geanta Neag Horia Ioan-B05471
Sent: Thursday, August 30, 2012 10:23 PM
To: Liu Qiang-B32616; linux-cry...@vger.kernel.org;
dan.j.willi...@gmail.com; herb...@gondor.hengli.com.au;
da...@davemloft.net; linux-ker...@vger.kernel.org; linuxppc-
d...@lists.ozlabs.org
Cc: Li Yang-R58472; Phillips Kim-R1AAHA; vinod.k...@intel.com;
dan.j.willi...@intel.com; a...@arndb.de; gre...@linuxfoundation.org; Liu
Qiang-B32616
Subject: RE: [PATCH v7 1/8] Talitos: Support for async_tx XOR offload
On Thu, 9 Aug 2012 11:20:48 +0300, qiang@freescale.com wrote:
From: Qiang Liu qiang@freescale.com
Expose Talitos's XOR functionality to be used for RAID parity
calculation via the Async_tx layer.
Cc: Herbert Xu herb...@gondor.apana.org.au
Cc: David S. Miller da...@davemloft.net
Signed-off-by: Dipen Dudhat dipen.dud...@freescale.com
Signed-off-by: Maneesh Gupta maneesh.gu...@freescale.com
Signed-off-by: Kim Phillips kim.phill...@freescale.com
Signed-off-by: Vishnu Suresh vis...@freescale.com
Signed-off-by: Qiang Liu qiang@freescale.com
---
drivers/crypto/Kconfig |9 +
drivers/crypto/talitos.c | 413
++
drivers/crypto/talitos.h | 53 ++
3 files changed, 475 insertions(+), 0 deletions(-)
+static int talitos_alloc_chan_resources(struct dma_chan *chan)
+{
+ struct talitos_xor_chan *xor_chan;
+ struct talitos_xor_desc *desc;
+ LIST_HEAD(tmp_list);
+ int i;
+
+ xor_chan = container_of(chan, struct talitos_xor_chan, common);
+
+ if (!list_empty(xor_chan-free_desc))
+ return xor_chan-total_desc;
+
+ for (i = 0; i TALITOS_MAX_DESCRIPTOR_NR; i++) {
+ desc = talitos_xor_alloc_descriptor(xor_chan,
+ GFP_KERNEL | GFP_DMA);
talitos_xor_alloc_descriptor() is called here without holding
the xor_chan-desc_lock and it increments xor_chan-total_desc.
Isn't this an issue ?
No, please refer to the code as below,
+ list_add_tail(desc-node, tmp_list);
The list is temporary list, it will be merged to xor_chan-free_desc in next
step, here is protected
by lock,
+ spin_lock_bh(xor_chan-desc_lock);
+ list_splice_init(tmp_list, xor_chan-free_desc);
+ spin_unlock_bh(xor_chan-desc_lock);
I was not referring to the list, but to xor_chan-total_desc variable.
The following access:
talitos_alloc_chan_resources()-talitos_xor_alloc_descriptor()-total_desc++
is not protected by the xor_chan-desc_lock.
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RE: [PATCH v7 1/8] Talitos: Support for async_tx XOR offload
-Original Message-
From: Geanta Neag Horia Ioan-B05471
Sent: Friday, August 31, 2012 6:39 PM
To: Liu Qiang-B32616; linux-cry...@vger.kernel.org;
dan.j.willi...@gmail.com; herb...@gondor.hengli.com.au;
da...@davemloft.net; linux-ker...@vger.kernel.org; linuxppc-
d...@lists.ozlabs.org
Cc: Li Yang-R58472; Phillips Kim-R1AAHA; vinod.k...@intel.com; Dan
Williams; a...@arndb.de; gre...@linuxfoundation.org
Subject: RE: [PATCH v7 1/8] Talitos: Support for async_tx XOR offload
On Fri, 31 Aug 2012 06:08:05 +0300, Liu Qiang-B32616
b32...@freescale.com
wrote:
-Original Message-
From: Geanta Neag Horia Ioan-B05471
Sent: Thursday, August 30, 2012 10:23 PM
To: Liu Qiang-B32616; linux-cry...@vger.kernel.org;
dan.j.willi...@gmail.com; herb...@gondor.hengli.com.au;
da...@davemloft.net; linux-ker...@vger.kernel.org; linuxppc-
d...@lists.ozlabs.org
Cc: Li Yang-R58472; Phillips Kim-R1AAHA; vinod.k...@intel.com;
dan.j.willi...@intel.com; a...@arndb.de; gre...@linuxfoundation.org;
Liu
Qiang-B32616
Subject: RE: [PATCH v7 1/8] Talitos: Support for async_tx XOR offload
On Thu, 9 Aug 2012 11:20:48 +0300, qiang@freescale.com wrote:
From: Qiang Liu qiang@freescale.com
Expose Talitos's XOR functionality to be used for RAID parity
calculation via the Async_tx layer.
Cc: Herbert Xu herb...@gondor.apana.org.au
Cc: David S. Miller da...@davemloft.net
Signed-off-by: Dipen Dudhat dipen.dud...@freescale.com
Signed-off-by: Maneesh Gupta maneesh.gu...@freescale.com
Signed-off-by: Kim Phillips kim.phill...@freescale.com
Signed-off-by: Vishnu Suresh vis...@freescale.com
Signed-off-by: Qiang Liu qiang@freescale.com
---
drivers/crypto/Kconfig |9 +
drivers/crypto/talitos.c | 413
++
drivers/crypto/talitos.h | 53 ++
3 files changed, 475 insertions(+), 0 deletions(-)
+static int talitos_alloc_chan_resources(struct dma_chan *chan)
+{
+ struct talitos_xor_chan *xor_chan;
+ struct talitos_xor_desc *desc;
+ LIST_HEAD(tmp_list);
+ int i;
+
+ xor_chan = container_of(chan, struct talitos_xor_chan,
common);
+
+ if (!list_empty(xor_chan-free_desc))
+ return xor_chan-total_desc;
+
+ for (i = 0; i TALITOS_MAX_DESCRIPTOR_NR; i++) {
+ desc = talitos_xor_alloc_descriptor(xor_chan,
+ GFP_KERNEL | GFP_DMA);
talitos_xor_alloc_descriptor() is called here without holding
the xor_chan-desc_lock and it increments xor_chan-total_desc.
Isn't this an issue ?
No, please refer to the code as below,
+ list_add_tail(desc-node, tmp_list);
The list is temporary list, it will be merged to xor_chan-free_desc in
next step, here is protected
by lock,
+ spin_lock_bh(xor_chan-desc_lock);
+ list_splice_init(tmp_list, xor_chan-free_desc);
+ spin_unlock_bh(xor_chan-desc_lock);
I was not referring to the list, but to xor_chan-total_desc variable.
The following access:
talitos_alloc_chan_resources()-talitos_xor_alloc_descriptor()-
total_desc++
is not protected by the xor_chan-desc_lock.
Ok, I will correct it in next series. Thanks.
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Re: [RFC v8 PATCH 00/20] memory-hotplug: hot-remove physical memory
On Tue, 28 Aug 2012 18:00:07 +0800
we...@cn.fujitsu.com wrote:
This patch series aims to support physical memory hot-remove.
Have you had much review and testing feedback yet?
The patches can free/remove the following things:
- acpi_memory_info : [RFC PATCH 4/19]
- /sys/firmware/memmap/X/{end, start, type} : [RFC PATCH 8/19]
- iomem_resource: [RFC PATCH 9/19]
- mem_section and related sysfs files : [RFC PATCH 10-11, 13-16/19]
- page table of removed memory : [RFC PATCH 12/19]
- node and related sysfs files : [RFC PATCH 18-19/19]
If you find lack of function for physical memory hot-remove, please let me
know.
I doubt if many people have hardware which permits physical memory
removal? How would you suggest that people with regular hardware can
test these chagnes?
Known problems:
1. memory can't be offlined when CONFIG_MEMCG is selected.
That's quite a problem! Do you have a description of why this is the
case, and a plan for fixing it?
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Re: [RFC v8 PATCH 04/20] memory-hotplug: offline and remove memory when removing the memory device
On Tue, 28 Aug 2012 18:00:11 +0800
we...@cn.fujitsu.com wrote:
+int remove_memory(int nid, u64 start, u64 size)
+{
+ int ret = -EBUSY;
+ lock_memory_hotplug();
+ /*
+ * The memory might become online by other task, even if you offine it.
+ * So we check whether the cpu has been onlined or not.
I think you meant memory, not cpu.
Actually, check whether any part of this memory range has been
onlined would be better. If that is accurate ;)
+ */
+ if (!is_memblk_offline(start, size)) {
+ pr_warn(memory removing [mem %#010llx-%#010llx] failed,
+ because the memmory range is online\n,
+ start, start + size);
+ ret = -EAGAIN;
+ }
+
+ unlock_memory_hotplug();
+ return ret;
+
+}
+EXPORT_SYMBOL_GPL(remove_memory);
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Re: [RFC v8 PATCH 08/20] memory-hotplug: remove /sys/firmware/memmap/X sysfs
On Tue, 28 Aug 2012 18:00:15 +0800
we...@cn.fujitsu.com wrote:
From: Yasuaki Ishimatsu isimatu.yasu...@jp.fujitsu.com
When (hot)adding memory into system, /sys/firmware/memmap/X/{end, start, type}
sysfs files are created. But there is no code to remove these files. The patch
implements the function to remove them.
Note : The code does not free firmware_map_entry since there is no way to free
memory which is allocated by bootmem.
+#define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry,
kobj)
It would be better to implement this as an inlined C function. That
has improved type safety and improved readability.
+static void release_firmware_map_entry(struct kobject *kobj)
+{
+ struct firmware_map_entry *entry = to_memmap_entry(kobj);
+ struct page *page;
+
+ page = virt_to_page(entry);
+ if (PageSlab(page) || PageCompound(page))
That PageCompound() test looks rather odd. Why is this done?
+ kfree(entry);
+
+ /* There is no way to free memory allocated from bootmem*/
+}
This function is a bit ugly - poking around in page flags to determine
whether or not the memory came from bootmem. It would be cleaner to
use a separate boolean. Although I guess we can live with it as you
have it here.
static struct kobj_type memmap_ktype = {
+ .release= release_firmware_map_entry,
.sysfs_ops = memmap_attr_ops,
.default_attrs = def_attrs,
};
@@ -123,6 +139,16 @@ static int firmware_map_add_entry(u64 start, u64 end,
return 0;
}
+/**
+ * firmware_map_remove_entry() - Does the real work to remove a firmware
+ * memmap entry.
+ * @entry: removed entry.
+ **/
+static inline void firmware_map_remove_entry(struct firmware_map_entry
*entry)
+{
+ list_del(entry-list);
+}
Is there no locking to protect that list?
/*
* Add memmap entry on sysfs
*/
@@ -144,6 +170,31 @@ static int add_sysfs_fw_map_entry(struct
firmware_map_entry *entry)
return 0;
}
+/*
+ * Remove memmap entry on sysfs
+ */
+static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry
*entry)
+{
+ kobject_put(entry-kobj);
+}
+
+/*
+ * Search memmap entry
+ */
+
+struct firmware_map_entry * __meminit
+find_firmware_map_entry(u64 start, u64 end, const char *type)
A better name would be firmware_map_find_entry(). To retain the (good)
convention that symbols exported from here all start with
firmware_map_.
+{
+ struct firmware_map_entry *entry;
+
+ list_for_each_entry(entry, map_entries, list)
+ if ((entry-start == start) (entry-end == end)
+ (!strcmp(entry-type, type)))
+ return entry;
+
+ return NULL;
+}
+
/**
* firmware_map_add_hotplug() - Adds a firmware mapping entry when we do
* memory hotplug.
@@ -196,6 +247,32 @@ int __init firmware_map_add_early(u64 start, u64 end,
const char *type)
return firmware_map_add_entry(start, end, type, entry);
}
+/**
+ * firmware_map_remove() - remove a firmware mapping entry
+ * @start: Start of the memory range.
+ * @end: End of the memory range.
+ * @type: Type of the memory range.
+ *
+ * removes a firmware mapping entry.
+ *
+ * Returns 0 on success, or -EINVAL if no entry.
+ **/
+int __meminit firmware_map_remove(u64 start, u64 end, const char *type)
+{
+ struct firmware_map_entry *entry;
+
+ entry = find_firmware_map_entry(start, end - 1, type);
+ if (!entry)
+ return -EINVAL;
+
+ firmware_map_remove_entry(entry);
+
+ /* remove the memmap entry */
+ remove_sysfs_fw_map_entry(entry);
+
+ return 0;
+}
Again, the lack of locking looks bad.
...
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1052,9 +1052,9 @@ int offline_memory(u64 start, u64 size)
return 0;
}
-int remove_memory(int nid, u64 start, u64 size)
+int __ref remove_memory(int nid, u64 start, u64 size)
Why was __ref added?
{
- int ret = -EBUSY;
+ int ret = 0;
lock_memory_hotplug();
/*
* The memory might become online by other task, even if you offine it.
...
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Re: [RFC v8 PATCH 13/20] memory-hotplug: check page type in get_page_bootmem
On Tue, 28 Aug 2012 18:00:20 +0800
we...@cn.fujitsu.com wrote:
From: Yasuaki Ishimatsu isimatu.yasu...@jp.fujitsu.com
There is a possibility that get_page_bootmem() is called to the same page many
times. So when get_page_bootmem is called to the same page, the function only
increments page-_count.
I really don't understand this explanation, even after having looked at
the code. Can you please have another attempt at the changelog?
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -95,10 +95,17 @@ static void release_memory_resource(struct resource *res)
static void get_page_bootmem(unsigned long info, struct page *page,
unsigned long type)
{
- page-lru.next = (struct list_head *) type;
- SetPagePrivate(page);
- set_page_private(page, info);
- atomic_inc(page-_count);
+ unsigned long page_type;
+
+ page_type = (unsigned long) page-lru.next;
+ if (page_type MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
+ page_type MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE){
+ page-lru.next = (struct list_head *) type;
+ SetPagePrivate(page);
+ set_page_private(page, info);
+ atomic_inc(page-_count);
+ } else
+ atomic_inc(page-_count);
}
And a code comment which explains what is going on would be good. As
is always the case ;)
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