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| author | Hassan Naveed <hnaveed@wavecomp.com> | 2019-11-15 23:44:42 +0000 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2019-11-22 19:47:41 -0500 |
| commit | 0e24220821b0e0e330a18bfef29ac6396545d62e (patch) | |
| tree | b184533336bdad135bc7f38b3c06bceaac9c661b /arch/Kconfig | |
| parent | 89ed42495ef4a020435f2b999093bb5731eeb8b9 (diff) | |
| download | lwn-0e24220821b0e0e330a18bfef29ac6396545d62e.tar.gz lwn-0e24220821b0e0e330a18bfef29ac6396545d62e.zip | |
tracing: Use xarray for syscall trace events
Currently, a lot of memory is wasted for architectures like MIPS when
init_ftrace_syscalls() allocates the array for syscalls using kcalloc.
This is because syscalls numbers start from 4000, 5000 or 6000 and
array elements up to that point are unused.
Fix this by using a data structure more suited to storing sparsely
populated arrays. The XARRAY data structure, implemented using radix
trees, is much more memory efficient for storing the syscalls in
question.
Link: http://lkml.kernel.org/r/20191115234314.21599-1-hnaveed@wavecomp.com
Signed-off-by: Hassan Naveed <hnaveed@wavecomp.com>
Reviewed-by: Paul Burton <paulburton@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'arch/Kconfig')
| -rw-r--r-- | arch/Kconfig | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 5f8a5d84dbbe..69c87e8608d8 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -960,6 +960,14 @@ config RELR config ARCH_HAS_MEM_ENCRYPT bool +config HAVE_SPARSE_SYSCALL_NR + bool + help + An architecture should select this if its syscall numbering is sparse + to save space. For example, MIPS architecture has a syscall array with + entries at 4000, 5000 and 6000 locations. This option turns on syscall + related optimizations for a given architecture. + source "kernel/gcov/Kconfig" source "scripts/gcc-plugins/Kconfig" |