rocm-smi with superuser permission doesn't show some
of smi events, i.e. page fault/migration, because the
condition of "(events & all)" is false. Superuser
should be able to detect all events, the condiiton of
"(events & all)" seems redundant, so removing it will
fix the issue.
Signed-off-by: Eric Huang <jinhuieric.huang@amd.com>
Reviewed-by: Kent Russell <kent.russell@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
The mistake will lead to NULL kernel oops, so fix it.
Fixes: 4172b556fd ("drm/amdkfd: add smi events for process start and end")
Signed-off-by: Eric Huang <jinhuieric.huang@amd.com>
Reviewed-by: Kent Russell <kent.russell@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This patch adds recommended SDMA engines with limited XGMI SDMA engines.
It will help improve overall performance for device to device copies
with this optimization.
v2: Update the formatting issues and data type
Signed-off-by: Shane Xiao <shane.xiao@amd.com>
Suggested-by: Jonathan Kim <jonathan.kim@amd.com>
Reviewed-by: Jonathan Kim <jonathan.kim@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
rocm-smi will be able to show the events for KFD process
start/end, it is the implementation of this feature.
Signed-off-by: Eric Huang <jinhuieric.huang@amd.com>
Reviewed-by: Kent Russell <kent.russell@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Switch from a bool to an enum and allow more options
for enforce isolation. There are now 3 modes of operation:
- Disabled (0)
- Enabled (serialization and cleaner shader) (1)
- Enabled in legacy mode (no serialization or cleaner shader) (2)
This provides better flexibility for more use cases.
Acked-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Remove workaround code for the early engineering
samples GC v9.4.3 SOCs with revID 0
Reviewed-by: Amber Lin <Amber.Lin@amd.com>
Signed-off-by: Apurv Mishra <Apurv.Mishra@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
To get the device context, replace pr_ with dev_ functions.
Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
ASICs post GFX 9 are being flagged as SDMA per queue reset supported
in the KGD but KFD and scheduler FW currently have no support.
Limit SDMA queue reset capabilities to GFX 9.
Fixes: ceb7114c96 ("drm/amdkfd: flag per-sdma queue reset supported to user space")
Signed-off-by: Jonathan Kim <jonathan.kim@amd.com>
Reviewed-by: David Belanger <david.belanger@amd.com>
Reviewed-by: Harish Kasiviswanathan <harish.kasiviswanathan@amd.com>
Reviewed-by: Jesse Zhang <jesse.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Disable per queue reset for sriov.
Signed-off-by: Emily Deng <Emily.Deng@amd.com>
Reviewed-by: Jonathan Kim <jonathan.kim@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Move the kfd suspend/resume code into the caller. That
is where the KFD is likely to detect a reset so on the KFD
side there is no need to call them. Also add a mutex to
lock the actual reset sequence.
v2: make the locking per instance
Fixes: bac38ca8c4 ("drm/amdkfd: implement per queue sdma reset for gfx 9.4+")
Reviewed-by: Jesse Zhang <jesse.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Clause instructions with precise memory enabled currently hang the
shader so set capabilities flag to disabled since it's unsafe to use
for debugging.
Signed-off-by: Jonathan Kim <jonathan.kim@amd.com>
Tested-by: Lancelot Six <lancelot.six@amd.com>
Reviewed-by: Harish Kasiviswanathan <harish.kasiviswanathan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
For certain ASICs where dequeue_wait_count don't need to be initialized,
pm_config_dequeue_wait_counts_v9 return without filling in the packet
information. However, the calling function interprets this as a success
and sends the uninitialized packet to firmware causing hang.
Fix the above bug by not calling pm_config_dequeue_wait_counts_v9 for
ASICs that don't need the value to be initialized.
v2: Removed redudant code.
Tidy up code based on review comments
v3: Don't call pm_config_dequeue_wait_counts_v9 for certain ASICs
Fixes: ed962f8d06 ("drm/amdkfd: Add pm_config_dequeue_wait_counts API")
Signed-off-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Reviewed-by: Jonathan Kim <jonathan.kim@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Always use MTYPE_UC if UNCACHED flag is specified.
This makes kernarg region uncached and it restores
usermode cache disable debug flag functionality.
Do not set MTYPE_UC for COHERENT flag, on GFX12 coherence is handled by
shader code.
Signed-off-by: David Belanger <david.belanger@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Correct F8_MODE setting for gfx950 that was removed
Fixes: 61972cd93a ("drm/amdkfd: Set per-process flags only once for gfx9/10/11/12")
Signed-off-by: Amber Lin <Amber.Lin@amd.com>
Reviewed-by: Harish Kasiviswanathan <Harish.Kasiviwanathan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
In sriov multiple vf, Set CP_HQD_PQ_DOORBELL_CONTROL.DOORBELL_MODE to 1 to read WPTR from MQD.
Signed-off-by: Emily Deng <Emily.Deng@amd.com>
Acked-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
VALU instructions with SGPR source need wait states to avoid hazard
with SALU using different SGPR.
v2: Eliminate some hazards to reduce code explosion
Signed-off-by: Jay Cornwall <jay.cornwall@amd.com>
Reviewed-by: Lancelot Six <lancelot.six@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Dequeue retry timeout controls the interval between checks for unmet
conditions. On MI series, reduce this from 0x40 to 0x1 (~ 1 uS). The
cost of additional bandwidth consumed by CP when polling memory
shouldn't be substantial.
Signed-off-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Reviewed-by: Jonathan Kim <jonathan.kim@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Issue:
In the scenario where svm_range_restore_pages is called, but
svm->checkpoint_ts has not been set and the retry fault has not been
drained, svm_range_unmap_from_cpu is triggered and calls svm_range_free.
Meanwhile, svm_range_restore_pages continues execution and reaches
svm_range_from_addr. This results in a "failed to find prange..." error,
causing the page recovery to fail.
How to fix:
Move the timestamp check code under the protection of svm->lock.
v2:
Make sure all right locks are released before go out.
v3:
Directly goto out_unlock_svms, and return -EAGAIN.
v4:
Refine code.
Signed-off-by: Emily Deng <Emily.Deng@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why]
If reset is detected and kfd need to evict working queues, HWS moving queue will be failed.
Then remaining queues are not evicted and in active state.
After reset done, kfd uses HWS to termination remaining activated queues but HWS is resetted.
So remove queue will be failed again.
[How]
Keep removing all queues even if HWS returns failed.
It will not affect cpsch as it checks reset_domain->sem.
v2: If any queue failed, evict queue returns error.
v3: Declare err inside the if-block.
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Yifan Zha <Yifan.Zha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
These lines are indented one tab more than they should be. Delete
the stray tabs.
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Update pm_update_grace_period() to more cleaner
pm_config_dequeue_wait_counts(). Previously, grace_period variable was
overloaded as a variable and a macro, making it inflexible to configure
additional dequeue wait times.
pm_config_dequeue_wait_counts() now takes in a cmd / variable. This
allows flexibility to update different dequeue wait times.
Signed-off-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Reviewed-by: Jonathan Kim <jonathan.kim@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Add support for more per-process flags starting with option to configure
MFMA precision for gfx 9.5
v2: Change flag name to KFD_PROC_FLAG_MFMA_HIGH_PRECISION
Remove unused else condition
v3: Bump the KFD API version
v4: Missed SH_MEM_CONFIG__PRECISION_MODE__SHIFT define. Added it.
Signed-off-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Reviewed-by: Amber Lin <Amber.Lin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Define set_cache_memory_policy() for these asics and move all static
changes from update_qpd() which is called each time a queue is created
to set_cache_memory_policy() which is called once during process
initialization
Signed-off-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Reviewed-by: Amber Lin <Amber.Lin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Set per-process static sh_mem config only once during process
initialization. Move all static changes from update_qpd() which is
called each time a queue is created to set_cache_memory_policy() which
is called once during process initialization.
set_cache_memory_policy() is currently defined only for cik and vi
family. So this commit only focuses on these two. A separate commit will
address other asics.
Signed-off-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Reviewed-by: Amber Lin <Amber.Lin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Default F8_MODE should be OCP format on gfx950.
Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Reviewed-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Signed-off-by: Amber Lin <Amber.Lin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
While the entry get in svm_range_unmap_from_cpu is the last entry, and
the entry is page fault, it also need to be dropped. So for equal case,
it also need to be dropped.
v2:
Only modify the svm_range_restore_pages.
Signed-off-by: Emily Deng <Emily.Deng@amd.com>
Reviewed-by: Xiaogang Chen<xiaogang.chen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Remove unused declaration of gws_debug_workaround.
Signed-off-by: Jonathan Kim <jonathan.kim@amd.com>
Reviewed-by: Amber Lin <amber.lin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Similar to compute queue reset, flag SDMA queue reset capabilities to
user space for safe testing.
Signed-off-by: Jonathan Kim <jonathan.kim@amd.com>
Reviewed-by: Harish Kasiviswanathan <harish.kasiviswanathan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
To reset hung SDMA queues on GFX 9.4+ for the GFX9 family, a soft reset
must be issued through SMU. Since soft resets will reset an entire SDMA
engine, use a common KGD call to do the reset as the KGD will handle
avoiding a reset of in flight GFX and paging queues on that engine.
In addition, create a common call for all reset types to simplify
the handling of module parameter settings that block gpu resets.
Signed-off-by: Jonathan Kim <jonathan.kim@amd.com>
Reviewed-by: Harish Kasiviswanathan <harish.kasiviswanathan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Through KFD IOCTL Fuzzing we encountered a NULL pointer derefrence
when calling kfd_queue_acquire_buffers.
Fixes: 629568d25f ("drm/amdkfd: Validate queue cwsr area and eop buffer size")
Signed-off-by: Andrew Martin <Andrew.Martin@amd.com>
Reviewed-by: Philip Yang <Philip.Yang@amd.com>
Signed-off-by: Andrew Martin <Andrew.Martin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
pqm_get_kernel_queue() has been unused since 2022's
commit 5bdd3eb253 ("drm/amdkfd: Remove unused old debugger
implementation")
Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
debugfs hang_hws is used by GPU reset test with HWS, for MES this crash
the kernel with NULL pointer access because dqm->packet_mgr is not setup
for MES path.
Skip GPU with MES for now, MES hang_hws debugfs interface will be
supported later.
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Kent Russell <kent.russell@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
If GPU in reset, destroy_queue return -EIO, pqm_destroy_queue should
delete the queue from process_queue_list and free the resource.
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
If HW scheduler hangs and mode1 reset is used to recover GPU, KFD signal
user space to abort the processes. After process abort exit, user queues
still use the GPU to access system memory before h/w is reset while KFD
cleanup worker free system memory and free VRAM.
There is use-after-free race bug that KFD allocate and reuse the freed
system memory, and user queue write to the same system memory to corrupt
the data structure and cause driver crash.
To fix this race, KFD cleanup worker terminate user queues, then flush
reset_domain wq to wait for any GPU ongoing reset complete, and then
free outstanding BOs.
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
If waiting for gpu reset done in KFD release_work, thers is WARNING:
possible circular locking dependency detected
#2 kfd_create_process
kfd_process_mutex
flush kfd release work
#1 kfd release work
wait for amdgpu reset work
#0 amdgpu_device_gpu_reset
kgd2kfd_pre_reset
kfd_process_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock((work_completion)(&p->release_work));
lock((wq_completion)kfd_process_wq);
lock((work_completion)(&p->release_work));
lock((wq_completion)amdgpu-reset-dev);
To fix this, KFD create process move flush release work outside
kfd_process_mutex.
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
With GPU reset-domain worker implemented, KFD hw_exception worker is not
needed any more, just call amdgpu_amdkfd_gpu_reset directly from
kfd_hws_hang.
Suggested-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Since kfd uses pasid values from graphic driver now do not need use kfd pasid
fucntions.
Signed-off-by: Xiaogang Chen <xiaogang.chen@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
If queue size is less than minimum, clamp it to minimum to prevent
underflow when writing queue mqd.
Signed-off-by: David Yat Sin <David.YatSin@amd.com>
Reviewed-by: Jay Cornwall <jay.cornwall@amd.com>
Reviewed-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Deprecate KFD XGMI peer info calls in favour of calling directly from
simplified XGMI peer info functions.
Signed-off-by: Jonathan Kim <jonathan.kim@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Even though GWS no longer exists, to maintain runtime usage for
cooperative launch, SW set legacy GWS size.
Signed-off-by: Jonathan Kim <jonathan.kim@amd.com>
Acked-by: Mukul Joshi <mukul.joshi@amd.com>
Reviewed-by: Harish Kasiviswanathan <harish.kasiviswanathan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
When userspace applications call AMDKFD_IOC_UPDATE_QUEUE. Preserve
bitfields that do not need to be modified as they contain flags to
track queue states that are used by CP FW.
Signed-off-by: David Yat Sin <David.YatSin@amd.com>
Reviewed-by: Jay Cornwall <jay.cornwall@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
In the kfd_process_device_init_vm function, a valid error code is now
returned when the associated Process Address Space ID (PASID) is not
present.
If the address space virtual memory (avm) does not have an associated
PASID, the function sets the ret variable to -EINVAL before proceeding
to the error handling section. This ensures that the calling function,
such as kfd_ioctl_acquire_vm, can appropriately handle the error,
thereby preventing any issues during virtual memory initialization.
Fixes the below:
drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_process.c:1694 kfd_process_device_init_vm()
warn: missing error code 'ret'
drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_process.c
1647 int kfd_process_device_init_vm(struct kfd_process_device *pdd,
1648 struct file *drm_file)
1649 {
...
1690
1691 if (unlikely(!avm->pasid)) {
1692 dev_warn(pdd->dev->adev->dev, "WARN: vm %p has no pasid associated",
1693 avm);
--> 1694 goto err_get_pasid;
ret = -EINVAL?
1695 }
Fixes: 8544374c0f ("drm/amdkfd: Have kfd driver use same PASID values from graphic driver")
Reported by: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Xiaogang Chen <xiaogang.chen@amd.com>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
To workaround queue full h/w issue on Gfx7/8, when application create
AQL queue, the ring buffer bo allocate size is queue_size/2 and
map queue_size ring buffer to GPU in 2 pieces using 2 attachments, each
attachment map size is queue_size/2, with same ring_bo backing memory.
For Gfx7/8, user queue buffer validation should use queue_size/2 to
verify ring_bo allocation and mapping size.
Fixes: 68e599db7a ("drm/amdkfd: Validate user queue buffers")
Suggested-by: Tomáš Trnka <trnka@scm.com>
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Curret kfd does not allocate pasid values, instead uses pasid value for each
vm from graphic driver. So should not prevent graphic driver from releasing
pasid values since the values are allocated by graphic driver, not kfd driver
anymore. This patch does not stop graphic driver release pasid values.
Fixes: 8544374c0f ("drm/amdkfd: Have kfd driver use same PASID values from graphic driver")
Signed-off-by: Xiaogang Chen <xiaogang.chen@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
In some ASICs L2 cache info may miss in kfd topology,
because the first bitmap may be empty, that means
the first cu may be inactive, so to find the first
active cu will solve the issue.
v2: Only find the first active cu in the first xcc
Signed-off-by: Eric Huang <jinhuieric.huang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
find_system_memory() pulls out two fields from an SMBIOS type 17
device and sets them on KFD devices. The data offsets are counted
to find interesting data.
Instead use a struct representation to access the members and pull
out the two specific fields.
No intended functional changes.
Link: https://www.dmtf.org/sites/default/files/standards/documents/DSP0134_3.8.0.pdf p99
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Link: https://lore.kernel.org/r/20250206214847.3334595-1-superm1@kernel.org
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
On big and small APUs we send KFD VRAM allocations to GTT
since the carve out is either non-existent or relatively
small. However, if someone sets the carve out size to be
relatively large, we may end up using GTT rather than VRAM.
No change of logic with this patch, but it allows the
driver to determine which logic to use based on the
carve out size in the future.
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
kfd_device_by_pci_dev(), kfd_get_pasid_limit() and kfd_set_pasid_limit()
have been unused since 2023's
commit c99a2e7ae2 ("drm/amdkfd: drop IOMMUv2 support")
Remove them.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Current kfd driver has its own PASID value for a kfd process and uses it to
locate vm at interrupt handler or mapping between kfd process and vm. That
design is not working when a physical gpu device has multiple spatial
partitions, ex: adev in CPX mode. This patch has kfd driver use same pasid
values that graphic driver generated which is per vm per pasid.
These pasid values are passed to fw/hardware. We do not need change interrupt
handler though more pasid values are used. Also, pasid values at log are
replaced by user process pid; pasid values are not exposed to user. Users see
their process pids that have meaning in user space.
Signed-off-by: Xiaogang Chen <xiaogang.chen@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Eric Huang
Shane Xiao
Alex Deucher
Apurv Mishra
Lijo Lazar
Jonathan Kim
Emily Deng
Harish Kasiviswanathan
David Belanger
Amber Lin
Jay Cornwall
Yifan Zha
Dan Carpenter
Alex Sierra
Andrew Martin
Dr. David Alan Gilbert
Philip Yang
Xiaogang Chen
David Yat Sin
Srinivasan Shanmugam
Mario Limonciello