[CC+=hpa] On 2/24/09, Michael Kerrisk <mtk.manpages@xxxxxxxxxxxxxx> wrote: > On 2/23/09, Andi Kleen <andi@xxxxxxxxxxxxxx> wrote: >> Here's a simple manpage for the msr device. >> >> -Andi > > Thanks for this page Andi. > > A few comments/questions below. > >> .\" Some sentences copied from comment in arch/x86/kernel/msr.c >> .TH MSR 7 2009-02-22 "Linux" "Linux Programmer's Manual" >> .SH NAME >> msr \- x86 CPU MSR access device >> .SH DESCRIPTION >> .I /dev/cpu/CPUNUM/msr >> allows to read and write the model specific registers (MSRs) of an x86 >> CPU. >> .I CPUNUM >> is the number of the cpu to access as listed in >> .I /proc/cpuinfo. >> The register access is done by opening the file and seeking to the MSR >> number > > Could you clarify "seek to the MSR number" == does that mean seek to > offset (MSR_number * 8) or something like that? > >> as offset in the file and then read or write in chunks of 8 bytes. >> A larger size than 8 bytes means multiple reads or writes of the >> same register. > > What are the semantics of reading the same register multiple times? > Is a read non-destructive? Do the multiple reads always get the same > value? > > Cheers, > > Michael > >> .SH NOTES >> The >> .I msr >> driver is not auto-loaded. On modular kernel you might need to use >> .B modprobe msr >> to load it explicitely before use. >> .SH SEE ALSO >> Intel Corporation Intel 64 and IA-32 Architectures Software Developer's >> Manual Volume 3B Appendix B >> for an overview of the Intel CPU MSRs. >> > > > -- > Michael Kerrisk > Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ > git://git.kernel.org/pub/scm/docs/man-pages/man-pages.git > man-pages online: http://www.kernel.org/doc/man-pages/online_pages.html > Found a bug? http://www.kernel.org/doc/man-pages/reporting_bugs.html > -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ git://git.kernel.org/pub/scm/docs/man-pages/man-pages.git man-pages online: http://www.kernel.org/doc/man-pages/online_pages.html Found a bug? http://www.kernel.org/doc/man-pages/reporting_bugs.html -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
