x86/sgx: Rename fallback labels in sgx_init()
Subsystems (3)
Jarkko Sakkinen
maintainerPATCH v6 1/2 x86/sgx: Rename fallback labels in sgx_init()
It's hard to add new content to this function because it is time consuming to match fallback and its cause. Rename labels in a way that the name of error label refers to the site where failure happened. This way it is easier to keep on track what is going on.
---
v5:
* A new patch.
arch/x86/kernel/cpu/sgx/main.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
arch/x86/kernel/cpu/sgx/main.c +6 -6
@@ -803,12 +803,12 @@ static int __init sgx_init(void)if (!sgx_page_reclaimer_init ()) { ret = -ENOMEM ; - goto err_page_cache; + goto err_reclaimer; } ret =misc_register (&sgx_dev_provision);if (ret) - goto err_kthread; + goto err_provision;/* * Always try to initialize the native *and* KVM drivers.
@@ -821,17 +821,17 @@ static int __init sgx_init(void) ret =sgx_drv_init ();if (sgx_vepc_init () && ret) - goto err_provision; + goto err_driver;return 0 ; -err_provision: +err_driver:misc_deregister (&sgx_dev_provision); -err_kthread: +err_provision:kthread_stop (ksgxd_tsk); -err_page_cache: +err_reclaimer:for (i =0 ; i < sgx_nr_epc_sections; i++) {vfree (sgx_epc_sections[i].pages);memunmap (sgx_epc_sections[i].virt_addr);
Signature · 1 line
2.25.1
Jarkko Sakkinen
maintainerPATCH v6 2/2 x86/sgx: Add an attribute for the amount of SGX memory in a NUMA node
The amount of SGX memory on the system is determined by the BIOS and it varies wildly between systems. It can be from dozens of MB's on desktops or VM's, up to many GB's on servers. Just like for regular memory, it is sometimes useful to know the amount of usable SGX memory in the system.
Add an attribute for the amount of SGX memory in bytes to each NUMA node. The path is /sys/devices/system/node/node[0-9]*/sgx/memory_size. Calculate these values by summing up EPC section sizes for each node during the driver initalization.
---
v6:
* Initialize node->size to zero in sgx_setup_epc_section(), when the node is first accessed. The bug report:
https://lore.kernel.org/linux-sgx/[email protected]/
v5:
* A new patch based on the discussion on
https://lore.kernel.org/linux-sgx/[email protected]/T/#t
Documentation/x86/sgx.rst | 14 ++++++ arch/x86/kernel/cpu/sgx/main.c | 91 ++++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/sgx.h | 2 + 3 files changed, 107 insertions(+)
Documentation/x86/sgx.rst +14 -0
@@ -250,3 +250,17 @@ user wants to deploy SGX applications both on the host and in guests on the same machine, the user should reserve enough EPC (by taking out total virtual EPC size of all SGX VMs from the physical EPC size) for host SGX applications so they can run with acceptable performance. + +Per NUMA node SGX attributes +============================ + +NUMA nodes devices expose SGX specific attributes in the following path: + + /sys/devices/system/node/node[0-9]*/sgx/ + +Attributes +---------- + +memory_size + Total available physical SGX memory, also known as Enclave + Page Cache (EPC), in bytes.
arch/x86/kernel/cpu/sgx/main.c +91 -0
118 lines not on this page · raw message
arch/x86/kernel/cpu/sgx/sgx.h +2 -0
@@ -39,6 +39,8 @@ struct sgx_epc_page {*/ struct sgx_numa_node {struct list_head free_page_list; +struct kobject *kobj; +unsigned long size;spinlock_t lock; };
Signature · 1 line
2.25.1
Re: [PATCH v6 2/2] x86/sgx: Add an attribute for the amount of SGX memory in a NUMA node
Quoted 19 lines · Jarkko Sakkinen
The amount of SGX memory on the system is determined by the BIOS and it varies wildly between systems. It can be from dozens of MB's on desktops or VM's, up to many GB's on servers. Just like for regular memory, it is sometimes useful to know the amount of usable SGX memory in the system.
Add an attribute for the amount of SGX memory in bytes to each NUMA node. The path is /sys/devices/system/node/node[0-9]*/sgx/memory_size. Calculate these values by summing up EPC section sizes for each node during the driver initalization.
Cc Greg Kroah-Hartman <[email protected]>Signed-off-by Jarkko Sakkinen <[email protected]>---
v6:
* Initializenode->sizeto zero insgx_setup_epc_section(), when the node is first accessed. The bug report:
https://lore.kernel.org/linux-sgx/[email protected]/
Quoted 5 lines
v5:
* A new patch based on the discussion on
https://lore.kernel.org/linux-sgx/[email protected]/T/#tDocumentation/x86/sgx.rst | 14 ++++++
sysfs files have to be documented in Documentation/ABI/ so that they can be automatically checked, and added to the documentation output properly. Please do that here as well.
Quoted 51 lines
arch/x86/kernel/cpu/sgx/main.c | 91 ++++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/sgx.h | 2 + 3 files changed, 107 insertions(+)Documentation/x86/sgx.rst +14
-0@@ -250,3 +250,17 @@ user wants to deploy SGX applications both on the host and in guests on the same machine, the user should reserve enough EPC (by taking out total virtual EPC size of all SGX VMs from the physical EPC size) for host SGX applications so they can run with acceptable performance. + +Per NUMA node SGX attributes +============================ + +NUMA nodes devices expose SGX specific attributes in the following path: + + /sys/devices/system/node/node[0-9]*/sgx/ + +Attributes +---------- + +memory_size + Total available physical SGX memory, also known as Enclave + Page Cache (EPC), in bytes.arch/x86/kernel/cpu/sgx/main.c +7
-0@@ -714,9 +714,11 @@ static bool __init sgx_page_cache_init(void)spin_lock_init (&sgx_numa_nodes[nid].lock);INIT_LIST_HEAD (&sgx_numa_nodes[nid].free_page_list);node_set (nid, sgx_numa_mask); + sgx_numa_nodes[nid].size =0 ; } sgx_epc_sections[i].node = &sgx_numa_nodes[nid]; + sgx_numa_nodes[nid].size += size; sgx_nr_epc_sections++; }@@ -790,6 +792,87 @@ int sgx_set_attribute(unsigned long *allowed_attributes, }EXPORT_SYMBOL_GPL (sgx_set_attribute); +#ifdef CONFIG_NUMA +static void sgx_numa_exit (void ) +{ +int nid; +
arch/x86/kernel/cpu/sgx/main.c int sgx_set_attribute(unsigned long *allowed_attributes, · line 809
Quoted 10 lines
arch/x86/kernel/cpu/sgx/main.c +10
-0+for (nid =0 ; nid <num_possible_nodes (); nid++) { +if (!sgx_numa_nodes[nid].kobj) +continue ; + +kobject_put (sgx_numa_nodes[nid].kobj); + } +} + +#define SGX_NODE_ATTR_RO (_name) \ + static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
Why are you dealing with a "raw" kobject? Shouldn't you have a device and use a device attribute?
Quoted 5 lines
arch/x86/kernel/cpu/sgx/main.c +5
-0+static bool sgx_numa_init (void ) +{ +struct sgx_numa_node *node; +struct device *dev; +int nid;
arch/x86/kernel/cpu/sgx/main.c int sgx_set_attribute(unsigned long *allowed_attributes, · line 850
Quoted 10 lines
arch/x86/kernel/cpu/sgx/main.c +10
-0+int ret; + +for (nid =0 ; nid <num_possible_nodes (); nid++) { +if (!sgx_numa_nodes[nid].size) +continue ; + + node = &sgx_numa_nodes[nid]; + dev = &node_devices[nid]->dev; + + node->kobj =kobject_create_and_add ("sgx" , &dev->kobj);
You just "broke" the tree by putting a raw kobject below a struct device. Please do not do that.
arch/x86/kernel/cpu/sgx/main.c int sgx_set_attribute(unsigned long *allowed_attributes, · line 856
Quoted 6 lines
arch/x86/kernel/cpu/sgx/main.c +6
-0+if (!node->kobj) { +sgx_numa_exit (); +return false; + } + + ret =sysfs_create_group (node->kobj, &sgx_node_attr_group);
And you raced with userspace and lost.
Wait, you have a kobject _just_ for a subdirectory name? Why? Use a named attribute group, that's exactly what that is for.
Properly attach your attributes to the device you have, don't do extra work and complex code that you do not have to at all.
thanks,
greg k-h
Jarkko Sakkinen
maintainerRe: [PATCH v6 2/2] x86/sgx: Add an attribute for the amount of SGX memory in a NUMA node
Quoted 24 lines · Greg Kroah-Hartman
Quoted 23 lines · Jarkko Sakkinen
The amount of SGX memory on the system is determined by the BIOS and it varies wildly between systems. It can be from dozens of MB's on desktops or VM's, up to many GB's on servers. Just like for regular memory, it is sometimes useful to know the amount of usable SGX memory in the system.
Add an attribute for the amount of SGX memory in bytes to each NUMA node. The path is /sys/devices/system/node/node[0-9]*/sgx/memory_size. Calculate these values by summing up EPC section sizes for each node during the driver initalization.
Cc Greg Kroah-Hartman <[email protected]>Signed-off-by Jarkko Sakkinen <[email protected]>---
v6:
* Initializenode->sizeto zero insgx_setup_epc_section(), when the node is first accessed. The bug report:
https://lore.kernel.org/linux-sgx/[email protected]/v5:
* A new patch based on the discussion on
https://lore.kernel.org/linux-sgx/[email protected]/T/#t
Quoted 5 lines
Quoted 1 line
Documentation/x86/sgx.rst | 14 ++++++sysfs files have to be documented in
Documentation/ABI/so that they can be automatically checked, and added to the documentation output properly. Please do that here as well.
Right, I'll document it to sysfs-devices-node.
Quoted 75 lines
Quoted 51 lines
arch/x86/kernel/cpu/sgx/main.c | 91 ++++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/sgx.h | 2 + 3 files changed, 107 insertions(+)Documentation/x86/sgx.rst +14
-0@@ -250,3 +250,17 @@ user wants to deploy SGX applications both on the host and in guests on the same machine, the user should reserve enough EPC (by taking out total virtual EPC size of all SGX VMs from the physical EPC size) for host SGX applications so they can run with acceptable performance. + +Per NUMA node SGX attributes +============================ + +NUMA nodes devices expose SGX specific attributes in the following path: + + /sys/devices/system/node/node[0-9]*/sgx/ + +Attributes +---------- + +memory_size + Total available physical SGX memory, also known as Enclave + Page Cache (EPC), in bytes.arch/x86/kernel/cpu/sgx/main.c +7
-0@@ -714,9 +714,11 @@ static bool __init sgx_page_cache_init(void)spin_lock_init (&sgx_numa_nodes[nid].lock);INIT_LIST_HEAD (&sgx_numa_nodes[nid].free_page_list);node_set (nid, sgx_numa_mask); + sgx_numa_nodes[nid].size =0 ; } sgx_epc_sections[i].node = &sgx_numa_nodes[nid]; + sgx_numa_nodes[nid].size += size; sgx_nr_epc_sections++; }@@ -790,6 +792,87 @@ int sgx_set_attribute(unsigned long *allowed_attributes, }EXPORT_SYMBOL_GPL (sgx_set_attribute); +#ifdef CONFIG_NUMA +static void sgx_numa_exit (void ) +{ +int nid; +arch/x86/kernel/cpu/sgx/main.c int sgx_set_attribute(unsigned long *allowed_attributes, · line 809
Quoted 10 lines
arch/x86/kernel/cpu/sgx/main.c +10
-0+for (nid =0 ; nid <num_possible_nodes (); nid++) { +if (!sgx_numa_nodes[nid].kobj) +continue ; + +kobject_put (sgx_numa_nodes[nid].kobj); + } +} + +#define SGX_NODE_ATTR_RO (_name) \ + static struct kobj_attribute _name##_attr = __ATTR_RO(_name)Why are you dealing with a "raw" kobject? Shouldn't you have a device and use a device attribute?
Quoted 10 lines
arch/x86/kernel/cpu/sgx/main.c +10
-0+static bool sgx_numa_init (void ) +{ +struct sgx_numa_node *node; +struct device *dev; +int nid; +int ret; + +for (nid =0 ; nid <num_possible_nodes (); nid++) { +if (!sgx_numa_nodes[nid].size) +continue ;
Quoted 8 lines
arch/x86/kernel/cpu/sgx/main.c int sgx_set_attribute(unsigned long *allowed_attributes, · line 850
Quoted 5 lines
arch/x86/kernel/cpu/sgx/main.c +5
-0+ + node = &sgx_numa_nodes[nid]; + dev = &node_devices[nid]->dev; + + node->kobj =kobject_create_and_add ("sgx" , &dev->kobj);You just "broke" the tree by putting a raw kobject below a struct device. Please do not do that.
I looked how hugetlb was implemented as a starting point, since it is existing mainline code, i.e. in mm/hugetlb.c:
- hugetlb_register_node()
- hugetlb_register_all_nodes()
- HSTATE_ATTR_RO()
hugetlb code attaches raw kobjects to the node device, by using this (perhaps anti)pattern.
Quoted 10 lines
arch/x86/kernel/cpu/sgx/main.c int sgx_set_attribute(unsigned long *allowed_attributes, · line 856
Quoted 7 lines
arch/x86/kernel/cpu/sgx/main.c +6
-0+if (!node->kobj) { +sgx_numa_exit (); +return false; + } + + ret =sysfs_create_group (node->kobj, &sgx_node_attr_group);And you raced with userspace and lost.
Quoted 5 lines
Wait, you have a kobject _just_ for a subdirectory name? Why? Use a named attribute group, that's exactly what that is for.
Properly attach your attributes to the device you have, don't do extra work and complex code that you do not have to at all.
Here the reference was hugetlb_sysfs_init() and hugetlb_sysfs_add_hstate(). Agreed, that a named group would make a lot more sense.
Quoted 3 lines
thanks,
greg k-h
/Jarkko
Re: [PATCH v6 2/2] x86/sgx: Add an attribute for the amount of SGX memory in a NUMA node
Quoted 120 lines · Jarkko Sakkinen
Quoted 24 lines · Greg Kroah-Hartman
Quoted 23 lines · Jarkko Sakkinen
The amount of SGX memory on the system is determined by the BIOS and it varies wildly between systems. It can be from dozens of MB's on desktops or VM's, up to many GB's on servers. Just like for regular memory, it is sometimes useful to know the amount of usable SGX memory in the system.
Add an attribute for the amount of SGX memory in bytes to each NUMA node. The path is /sys/devices/system/node/node[0-9]*/sgx/memory_size. Calculate these values by summing up EPC section sizes for each node during the driver initalization.
Cc Greg Kroah-Hartman <[email protected]>Signed-off-by Jarkko Sakkinen <[email protected]>---
v6:
* Initializenode->sizeto zero insgx_setup_epc_section(), when the node is first accessed. The bug report:
https://lore.kernel.org/linux-sgx/[email protected]/v5:
* A new patch based on the discussion on
https://lore.kernel.org/linux-sgx/[email protected]/T/#tQuoted 5 lines
Quoted 1 line
Documentation/x86/sgx.rst | 14 ++++++sysfs files have to be documented in
Documentation/ABI/so that they can be automatically checked, and added to the documentation output properly. Please do that here as well.Right, I'll document it to sysfs-devices-node.
Quoted 75 lines
Quoted 51 lines
arch/x86/kernel/cpu/sgx/main.c | 91 ++++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/sgx.h | 2 + 3 files changed, 107 insertions(+)Documentation/x86/sgx.rst +14
-0@@ -250,3 +250,17 @@ user wants to deploy SGX applications both on the host and in guests on the same machine, the user should reserve enough EPC (by taking out total virtual EPC size of all SGX VMs from the physical EPC size) for host SGX applications so they can run with acceptable performance. + +Per NUMA node SGX attributes +============================ + +NUMA nodes devices expose SGX specific attributes in the following path: + + /sys/devices/system/node/node[0-9]*/sgx/ + +Attributes +---------- + +memory_size + Total available physical SGX memory, also known as Enclave + Page Cache (EPC), in bytes.arch/x86/kernel/cpu/sgx/main.c +7
-0@@ -714,9 +714,11 @@ static bool __init sgx_page_cache_init(void)spin_lock_init (&sgx_numa_nodes[nid].lock);INIT_LIST_HEAD (&sgx_numa_nodes[nid].free_page_list);node_set (nid, sgx_numa_mask); + sgx_numa_nodes[nid].size =0 ; } sgx_epc_sections[i].node = &sgx_numa_nodes[nid]; + sgx_numa_nodes[nid].size += size; sgx_nr_epc_sections++; }@@ -790,6 +792,87 @@ int sgx_set_attribute(unsigned long *allowed_attributes, }EXPORT_SYMBOL_GPL (sgx_set_attribute); +#ifdef CONFIG_NUMA +static void sgx_numa_exit (void ) +{ +int nid; +arch/x86/kernel/cpu/sgx/main.c int sgx_set_attribute(unsigned long *allowed_attributes, · line 809
Quoted 10 lines
arch/x86/kernel/cpu/sgx/main.c +10
-0+for (nid =0 ; nid <num_possible_nodes (); nid++) { +if (!sgx_numa_nodes[nid].kobj) +continue ; + +kobject_put (sgx_numa_nodes[nid].kobj); + } +} + +#define SGX_NODE_ATTR_RO (_name) \ + static struct kobj_attribute _name##_attr = __ATTR_RO(_name)Why are you dealing with a "raw" kobject? Shouldn't you have a device and use a device attribute?
Quoted 10 lines
arch/x86/kernel/cpu/sgx/main.c +10
-0+static bool sgx_numa_init (void ) +{ +struct sgx_numa_node *node; +struct device *dev; +int nid; +int ret; + +for (nid =0 ; nid <num_possible_nodes (); nid++) { +if (!sgx_numa_nodes[nid].size) +continue ;Quoted 8 lines
arch/x86/kernel/cpu/sgx/main.c int sgx_set_attribute(unsigned long *allowed_attributes, · line 850
Quoted 5 lines
arch/x86/kernel/cpu/sgx/main.c +5
-0+ + node = &sgx_numa_nodes[nid]; + dev = &node_devices[nid]->dev; + + node->kobj =kobject_create_and_add ("sgx" , &dev->kobj);You just "broke" the tree by putting a raw kobject below a struct device. Please do not do that.
I looked how hugetlb was implemented as a starting point, since it is existing mainline code, i.e. in
mm/hugetlb.c:
Quoted 6 lines
-
hugetlb_register_node()
-hugetlb_register_all_nodes()
-HSTATE_ATTR_RO()hugetlb code attaches raw kobjects to the node device, by using this (perhaps anti)pattern.
Never look at the memory code for how to use sysfs "properly" :)
It deals with raw kobjects as it is not tied into the driver model at all. You are, so do not try to route around it, userspace will not be happy with you if you do so.
Quoted 10 lines
Quoted 10 lines
arch/x86/kernel/cpu/sgx/main.c int sgx_set_attribute(unsigned long *allowed_attributes, · line 856
Quoted 7 lines
arch/x86/kernel/cpu/sgx/main.c +6
-0+if (!node->kobj) { +sgx_numa_exit (); +return false; + } + + ret =sysfs_create_group (node->kobj, &sgx_node_attr_group);And you raced with userspace and lost.
Quoted 8 lines
Quoted 5 lines
Wait, you have a kobject _just_ for a subdirectory name? Why? Use a named attribute group, that's exactly what that is for.
Properly attach your attributes to the device you have, don't do extra work and complex code that you do not have to at all.
Here the reference was
hugetlb_sysfs_init()andhugetlb_sysfs_add_hstate(). Agreed, that a named group would make a lot more sense.
Again, ignore all sysfs code for the memory subsystem please :)
thanks,
greg k-h
Jarkko Sakkinen
maintainerRe: [PATCH v6 2/2] x86/sgx: Add an attribute for the amount of SGX memory in a NUMA node
Quoted 146 lines · Greg Kroah-Hartman
Quoted 120 lines · Jarkko Sakkinen
Quoted 24 lines · Greg Kroah-Hartman
Quoted 23 lines · Jarkko Sakkinen
The amount of SGX memory on the system is determined by the BIOS and it varies wildly between systems. It can be from dozens of MB's on desktops or VM's, up to many GB's on servers. Just like for regular memory, it is sometimes useful to know the amount of usable SGX memory in the system.
Add an attribute for the amount of SGX memory in bytes to each NUMA node. The path is /sys/devices/system/node/node[0-9]*/sgx/memory_size. Calculate these values by summing up EPC section sizes for each node during the driver initalization.
Cc Greg Kroah-Hartman <[email protected]>Signed-off-by Jarkko Sakkinen <[email protected]>---
v6:
* Initializenode->sizeto zero insgx_setup_epc_section(), when the node is first accessed. The bug report:
https://lore.kernel.org/linux-sgx/[email protected]/v5:
* A new patch based on the discussion on
https://lore.kernel.org/linux-sgx/[email protected]/T/#tQuoted 5 lines
Quoted 1 line
Documentation/x86/sgx.rst | 14 ++++++sysfs files have to be documented in
Documentation/ABI/so that they can be automatically checked, and added to the documentation output properly. Please do that here as well.Right, I'll document it to sysfs-devices-node.
Quoted 75 lines
Quoted 51 lines
arch/x86/kernel/cpu/sgx/main.c | 91 ++++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/sgx.h | 2 + 3 files changed, 107 insertions(+)Documentation/x86/sgx.rst +14
-0@@ -250,3 +250,17 @@ user wants to deploy SGX applications both on the host and in guests on the same machine, the user should reserve enough EPC (by taking out total virtual EPC size of all SGX VMs from the physical EPC size) for host SGX applications so they can run with acceptable performance. + +Per NUMA node SGX attributes +============================ + +NUMA nodes devices expose SGX specific attributes in the following path: + + /sys/devices/system/node/node[0-9]*/sgx/ + +Attributes +---------- + +memory_size + Total available physical SGX memory, also known as Enclave + Page Cache (EPC), in bytes.arch/x86/kernel/cpu/sgx/main.c +7
-0@@ -714,9 +714,11 @@ static bool __init sgx_page_cache_init(void)spin_lock_init (&sgx_numa_nodes[nid].lock);INIT_LIST_HEAD (&sgx_numa_nodes[nid].free_page_list);node_set (nid, sgx_numa_mask); + sgx_numa_nodes[nid].size =0 ; } sgx_epc_sections[i].node = &sgx_numa_nodes[nid]; + sgx_numa_nodes[nid].size += size; sgx_nr_epc_sections++; }@@ -790,6 +792,87 @@ int sgx_set_attribute(unsigned long *allowed_attributes, }EXPORT_SYMBOL_GPL (sgx_set_attribute); +#ifdef CONFIG_NUMA +static void sgx_numa_exit (void ) +{ +int nid; +arch/x86/kernel/cpu/sgx/main.c int sgx_set_attribute(unsigned long *allowed_attributes, · line 809
Quoted 10 lines
arch/x86/kernel/cpu/sgx/main.c +10
-0+for (nid =0 ; nid <num_possible_nodes (); nid++) { +if (!sgx_numa_nodes[nid].kobj) +continue ; + +kobject_put (sgx_numa_nodes[nid].kobj); + } +} + +#define SGX_NODE_ATTR_RO (_name) \ + static struct kobj_attribute _name##_attr = __ATTR_RO(_name)Why are you dealing with a "raw" kobject? Shouldn't you have a device and use a device attribute?
Quoted 10 lines
arch/x86/kernel/cpu/sgx/main.c +10
-0+static bool sgx_numa_init (void ) +{ +struct sgx_numa_node *node; +struct device *dev; +int nid; +int ret; + +for (nid =0 ; nid <num_possible_nodes (); nid++) { +if (!sgx_numa_nodes[nid].size) +continue ;Quoted 8 lines
arch/x86/kernel/cpu/sgx/main.c int sgx_set_attribute(unsigned long *allowed_attributes, · line 850
Quoted 5 lines
arch/x86/kernel/cpu/sgx/main.c +5
-0+ + node = &sgx_numa_nodes[nid]; + dev = &node_devices[nid]->dev; + + node->kobj =kobject_create_and_add ("sgx" , &dev->kobj);You just "broke" the tree by putting a raw kobject below a struct device. Please do not do that.
I looked how hugetlb was implemented as a starting point, since it is existing mainline code, i.e. in
mm/hugetlb.c:Quoted 6 lines
-
hugetlb_register_node()
-hugetlb_register_all_nodes()
-HSTATE_ATTR_RO()hugetlb code attaches raw kobjects to the node device, by using this (perhaps anti)pattern.
Never look at the memory code for how to use sysfs "properly" :)
It deals with raw kobjects as it is not tied into the driver model at all. You are, so do not try to route around it, userspace will not be happy with you if you do so.
Quoted 12 lines
Quoted 12 lines
arch/x86/kernel/cpu/sgx/main.c int sgx_set_attribute(unsigned long *allowed_attributes, · line 856
Quoted 6 lines
arch/x86/kernel/cpu/sgx/main.c +6
-0+if (!node->kobj) { +sgx_numa_exit (); +return false; + } + + ret =sysfs_create_group (node->kobj, &sgx_node_attr_group);And you raced with userspace and lost.
Wait, you have a kobject _just_ for a subdirectory name? Why? Use a named attribute group, that's exactly what that is for.
Quoted 7 lines
Quoted 5 lines
Quoted 2 lines
Properly attach your attributes to the device you have, don't do extra work and complex code that you do not have to at all.
Here the reference was
hugetlb_sysfs_init()andhugetlb_sysfs_add_hstate(). Agreed, that a named group would make a lot more sense.Again, ignore all sysfs code for the memory subsystem please :)
OK, cool, thank you. I can do that.
Quoted 4 lines
thanks,
greg k-h
/Jarkko