On 12/14/20 12:43 PM, Alejandro Colomar wrote:
Reported-by: Heinrich Schuchardt <xypron.glpk@xxxxxx> Signed-off-by: Alejandro Colomar <alx.manpages@xxxxxxxxx>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@xxxxxx>
--- man2/cacheflush.2 | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/man2/cacheflush.2 b/man2/cacheflush.2 index aba625721..7a2eed506 100644 --- a/man2/cacheflush.2 +++ b/man2/cacheflush.2 @@ -86,6 +86,30 @@ On Linux, this call first appeared on the MIPS architecture, but nowadays, Linux provides a .BR cacheflush () system call on some other architectures, but with different arguments. +.SH NOTES +Unless you need the finer grained control that this system call provides, +you probably want to use the GCC built-in function +.BR __builtin___clear_cache (), +which provides a portable interface +across platforms supported by GCC and compatible compilers: +.PP +.in +4n +.EX +.BI "void __builtin___clear_cache(void *" begin ", void *" end ); +.EE +.in +.PP +On platforms that don't require instruction cache flushes, +.BR __builtin___clear_cache () +has no effect. +.PP +.IR Note : +Until GCC 9.1.0, +the prototype for this built-in function used +.I char * +instead of +.I void * +for the parameters. .SH BUGS Linux kernels older than version 2.6.11 ignore the .I addr
