Hi Reinette/Peter, On 3/7/24 16:53, Reinette Chatre wrote: > Hi Peter, > > On 3/7/2024 2:33 PM, Peter Newman wrote: >> Hi Reinette, >> >> On Thu, Mar 7, 2024 at 12:41 PM Reinette Chatre >> <reinette.chatre@xxxxxxxxx> wrote: >>> >>> Hi Peter, >>> >>> On 3/7/2024 10:57 AM, Peter Newman wrote: >>>> Hi Babu, >>>> >>>> On Mon, Mar 4, 2024 at 2:24 PM Moger, Babu <bmoger@xxxxxxx> wrote: >>>>> Based on our discussion, I am listing few examples here. Let me know if >>>>> I missed something. >>>>> >>>>> mount -t resctrl resctrl /sys/fs/resctrl/ >>>>> >>>>> 1. Assign both local and total counters to default group on domain 0 and 1. >>>>> $echo "//00=lt;01=lt" > /sys/fs/resctrl/info/L3_MON/mbm_assign_control >>>>> >>>>> $cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control >>>>> //00=lt;01=lt >>>>> >>>>> 2. Assign a total event to mon group inside the default group for both >>>>> domain 0 and 1. >>>>> >>>>> $mkdir /sys/fs/resctrl/mon_groups/mon_a >>>>> $echo "/mon_a/00+t;01+t" > >>>>> /sys/fs/resctrl/info/L3_MON/mbm_assign_control >>>>> >>>>> $cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control >>>>> //00=lt;01=lt >>>>> /mon_a/00=t;01=t >>>>> >>>>> 3. Assign a local event to non-default control mon group both domain 0 >>>>> and 1. >>>>> $mkdir /sys/fs/resctrl/ctrl_a >>>>> $echo "/ctrl_a/00=l;01=l" > >>>>> /sys/fs/resctrl/info/L3_MON/mbm_assign_control >>>>> >>>>> $cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control >>>>> //00=lt;01=lt >>>>> /mon_a/00=t;01=t >>>>> /ctrl_a/00=l;01=l >>>>> >>>>> 4. Assign a both counters to mon group inside another control >>>>> group(non-default). >>>>> $mkdir /sys/fs/resctrl/ctrl_a/mon_ab/ >>>>> $echo "ctrl_a/mon_ab/00=lt;01=lt" > >>>>> /sys/fs/resctrl/nfo/L3_MON/mbm_assign_contro >>>>> >>>>> $cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control >>>>> //00=lt;01=lt >>>>> /mon_a/00=t;01=t >>>>> /ctrl_a/00=l;01=l >>>>> ctrl_a/mon_ab/00=lt;01=lt >>>>> >>>>> 5. Unassign a counter to mon group inside another control >>>>> group(non-default). >>>>> $echo "ctrl_a/mon_ab/00-l;01-l" > >>>>> /sys/fs/resctrl/nfo/L3_MON/mbm_assign_control >>>>> >>>>> $cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control >>>>> //00=lt;01=lt >>>>> /mon_a/00=t;01=t >>>>> /ctrl_a/00=l;01=l >>>>> ctrl_a/mon_ab/00=t;01=t >>>>> >>>>> 6. Unassign all the counters on a specific group. >>>>> $echo "ctrl_a/mon_ab/00=_" > >>>>> /sys/fs/resctrl/nfo/L3_MON/mbm_assign_control >>>>> >>>>> $cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control >>>>> //00=lt;01=lt >>>>> /mon_a/00=t;01=t >>>>> /ctrl_a/00=l;01=l >>>>> ctrl_a/mon_ab/00=_;01=_ >>>> >>>> The use case I'm interested in is iterating 32 counters over 256 >>>> groups[1]. If it's not possible to reassign 32 counters in a single >>>> write system call, with just one IPI per domain per batch reassignment >>>> operation, then I don't see any advantage over the original proposal >>>> with the assignment control file in every group directory. We already >>>> had fine-grained control placing assign/unassign nodes throughout the >>>> directory hierarchy, with the scope implicit in the directory >>>> location. >>> >>> The intent of this interface is to support modification of several >>> groups with a single write. These examples only show impact to a single >>> group at a time, but multiple groups can be modified by separating >>> configurations with a "\n". I believe Babu was planning to add some >>> of these examples in his next iteration since it is not obvious yet. >>> >>>> >>>> The interface I proposed in [1] aims to reduce the per-domain IPIs by >>>> a factor of the number of counters, rather than sending off 2 rounds >>>> of IPIs to each domain for each monitoring group. >>> >>> I understood the proposed interface appeared to focus on one use case >>> while the goal is to find an interface to support all requirements. >>> With this proposed interface it it possible to make large scale changes >>> with a single sysfs write. >> >> Ok I see you requested[1] one such example earlier. >> >> From what I've read, is this what you had in mind of reassigning 32 >> counters from the first 16 groups to the next? >> >> I had found that it's hard to get a single write() syscall out of a >> string containing newlines, so I'm using one explicit call: > > Apologies but this is not clear to me, could you please elaborate? > > If you are referring to testing via shell you can try ANSI-C Quoting like: > echo -n $'c1/m1/00=_\nc2/m2/00=_\n' > >> >> write([mbm_assign_control fd], >> "/c1/m1/00=_;02=_;03=_;04=_;05=_;06=_;07=_;08=_;09=_;10=_;11=_;12=_;13=_;14=_;15=_\n" >> "/c1/m2/00=_;01=_;02=_;03=_;04=_;05=_;06=_;07=_;08=_;09=_;10=_;11=_;12=_;13=_;14=_;15=_\n" >> "/c1/m3/00=_;01=_;02=_;03=_;04=_;05=_;06=_;07=_;08=_;09=_;10=_;11=_;12=_;13=_;14=_;15=_\n" >> [...] >> "/c1/m14/00=_;01=_;02=_;03=_;04=_;05=_;06=_;07=_;08=_;09=_;10=_;11=_;12=_;13=_;14=_;15=_\n" >> "/c1/m15/00=_;01=_;02=_;03=_;04=_;05=_;06=_;07=_;08=_;09=_;10=_;11=_;12=_;13=_;14=_;15=_\n" >> "/c1/m16/00=lt;01=lt;02=lt;03=lt;04=lt;05=lt;06=lt;07=lt;08=lt;09=lt;10=lt;11=lt;12=lt;13=lt;14=lt;15=lt\n" >> "/c1/m17/00=lt;01=lt;02=lt;03=lt;04=lt;05=lt;06=lt;07=lt;08=lt;09=lt;10=lt;11=lt;12=lt;13=lt;14=lt;15=lt\n" >> "/c1/m18/00=lt;01=lt;02=lt;03=lt;04=lt;05=lt;06=lt;07=lt;08=lt;09=lt;10=lt;11=lt;12=lt;13=lt;14=lt;15=lt\n" >> [...] >> "/c1/m30/00=lt;01=lt;02=lt;03=lt;04=lt;05=lt;06=lt;07=lt;08=lt;09=lt;10=lt;11=lt;12=lt;13=lt;14=lt;15=lt\n" >> "/c1/m31/00=lt;01=lt;02=lt;03=lt;04=lt;05=lt;06=lt;07=lt;08=lt;09=lt;10=lt;11=lt;12=lt;13=lt;14=lt;15=lt\n", >> size); > > (so far no "/" needed as prefix) > > We could also consider some syntax to mean "all domains". For example, > if no domain given then it can mean "all domains"? Yea. Sound good to me. Will let you know if there are any troubles when I start working on it. I am also thinking about replacing the newline requirement for multiple groups. Domains separate by "," and groups separate by ";". Something like this.. "/c1/m1/00=_,01=_;/c1/m2/00=_,01=_;/c1/m3/00=lt,01=lt" Thoughts? > So, your example could possibly also be accomplished with a > > c1/m1/=_\nc1/m2/=_\nc1/m3/=_\n [...] c1/m16/=lt\nc1/m17/=lt\nc1/m18/=_\n [...] > > Any thoughts? > > Reinette -- Thanks Babu Moger
