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Diffstat (limited to 'manual/tunables.texi')
| -rw-r--r-- | manual/tunables.texi | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/manual/tunables.texi b/manual/tunables.texi index d72d7a5ec0..1bbdc88281 100644 --- a/manual/tunables.texi +++ b/manual/tunables.texi @@ -36,6 +36,8 @@ their own namespace. * POSIX Thread Tunables:: Tunables in the POSIX thread subsystem * Hardware Capability Tunables:: Tunables that modify the hardware capabilities seen by @theglibc{} +* Memory Related Tunables:: Tunables that control the use of memory by + @theglibc{}. @end menu @node Tunable names @@ -484,3 +486,36 @@ instead. This tunable is specific to i386 and x86-64. @end deftp + +@node Memory Related Tunables +@section Memory Related Tunables +@cindex memory related tunables + +@deftp {Tunable namespace} glibc.mem +This tunable namespace supports operations that affect the way @theglibc{} +and the process manage memory. +@end deftp + +@deftp Tunable glibc.mem.tagging +If the hardware supports memory tagging, this tunable can be used to +control the way @theglibc{} uses this feature. At present this is only +supported on AArch64 systems with the MTE extention; it is ignored for +all other systems. + +This tunable takes a value between 0 and 255 and acts as a bitmask +that enables various capabilities. + +Bit 0 (the least significant bit) causes the malloc subsystem to allocate +tagged memory, with each allocation being assigned a random tag. + +Bit 1 enables precise faulting mode for tag violations on systems that +support deferred tag violation reporting. This may cause programs +to run more slowly. + +Other bits are currently reserved. + +@Theglibc{} startup code will automatically enable memory tagging +support in the kernel if this tunable has any non-zero value. + +The default value is @samp{0}, which disables all memory tagging. +@end deftp |