Hello Eugene, On 04/14/2018 06:43 PM, Eugene Syromyatnikov wrote: > * man2/s390_sthyi.2 (.SH DESCRIPTION): Document the size of the > resp_buffer when function_code is 0. > (.SH NOTES): Document various aspects of the current implementation (the > lifted requirement for the response buffer alignment, the presence of in-kernel > cache), add description for the documentation URL. > > Co-Authored-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx> > Signed-off-by: Eugene Syromyatnikov <evgsyr@xxxxxxxxx> Thanks. Patch applied. Cheers, Michael > --- > man2/s390_sthyi.2 | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/man2/s390_sthyi.2 b/man2/s390_sthyi.2 > index fb77195..d13aace 100644 > --- a/man2/s390_sthyi.2 > +++ b/man2/s390_sthyi.2 > @@ -53,6 +53,9 @@ capacity information. > The > .I resp_buffer > argument specifies the address of a response buffer. > +When the > +.I function_code > +is 0, it has to be one page (4K) in size. > If the system call returns 0, > the response buffer will be filled with CPU capacity information. > Otherwise, the response buffer's content is unchanged. > @@ -126,6 +129,14 @@ to call it. > .PP > For details of the STHYI instruction, see > .UR https://www.ibm.com\:/support\:/knowledgecenter\:/SSB27U_6.3.0\:/com.ibm.zvm.v630.hcpb4\:/hcpb4sth.htm > +the documentation page > .UE . > +.PP > +When the system call interface is used, the response buffer doesn't > +have to fulfill alignment requirements described in the STHYI > +instruction definition. > +.PP > +The kernel caches the response (for up to one second, as of Linux 4.16). > +Subsequent system call invocations may return the cached response. > .SH SEE ALSO > .BR syscall (2) > -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
