diff options
author | Gregory Nutt <gnutt@nuttx.org> | 2013-05-18 11:15:37 -0600 |
---|---|---|
committer | Gregory Nutt <gnutt@nuttx.org> | 2013-05-18 11:15:37 -0600 |
commit | a3ff9266aa01c82830e29985b81ffc0a67e705e3 (patch) | |
tree | 1163f1f16fd342c834fc6ea3cf14415550f48d7f /nuttx/TODO | |
parent | c2468c3288753a778a9c12ff6f49e096d138f744 (diff) | |
download | px4-nuttx-a3ff9266aa01c82830e29985b81ffc0a67e705e3.tar.gz px4-nuttx-a3ff9266aa01c82830e29985b81ffc0a67e705e3.tar.bz2 px4-nuttx-a3ff9266aa01c82830e29985b81ffc0a67e705e3.zip |
Begnning of support for the STM32L15X family
Diffstat (limited to 'nuttx/TODO')
-rw-r--r-- | nuttx/TODO | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/nuttx/TODO b/nuttx/TODO index 8fd59533e..74bf4e78c 100644 --- a/nuttx/TODO +++ b/nuttx/TODO @@ -422,6 +422,20 @@ o Kernel Build unless incrementing the count unblocks a task; similarly, down decrements the count and does not call into the the kernel unless the count becomes negative the caller must be blocked. + + Update: + "I am thinking that there should be a "magic" global, user-accessible + variable that holds the PID of the currently executing thread; + basically the PID of the task at the head of the ready-to-run list. + This variable would have to be reset each time the head of the ready- + to-run list changes. + + "Then getpid() could be implemented in user space with no system call + by simply reading this variable. + + "This one would be easy: Just a change to include/nuttx/userspace.h, + configs/*/kernel/up_userspace.c, libc/, sched/sched_addreadytorun.c, and + sched/sched_removereadytorun.c. That would eliminate 59% of the syscalls." Status: Open Priority: Low-Medium. Right now, I do not know if these syscalls are a real performance issue or not. |