Hi Dave, On 5/2/2024 9:21 AM, Dave Martin wrote: > On Thu, Mar 28, 2024 at 08:06:50PM -0500, Babu Moger wrote: >> diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst >> index 2d96565501ab..64ec70637c66 100644 >> --- a/Documentation/arch/x86/resctrl.rst >> +++ b/Documentation/arch/x86/resctrl.rst >> @@ -328,6 +328,77 @@ with the following files: >> None of events are assigned on this mon group. This is a child >> monitor group of the non default control mon group. >> >> + Assignment state can be updated by writing to this interface. >> + >> + NOTE: Assignment on one domain applied on all the domains. User can >> + pass one valid domain and assignment will be updated on all the >> + available domains. >> + >> + Format is similar to the list format with addition of op-code for the >> + assignment operation. >> + >> + * Default CTRL_MON group: >> + "//<domain_id><op-code><assignment_flags>" >> + >> + * Non-default CTRL_MON group: >> + "<CTRL_MON group>//<domain_id><op-code><assignment_flags>" >> + >> + * Child MON group of default CTRL_MON group: >> + "/<MON group>/<domain_id><op-code><assignment_flags>" >> + >> + * Child MON group of non-default CTRL_MON group: >> + "<CTRL_MON group>/<MON group>/<domain_id><op-code><assignment_flags>" > > The final bullet seems to cover everything, if we allow <CTRL_MON group> > and <MON group> to be independently empty strings to indicate the > default control and/or monitoring group respectively. > > Would that be simpler than treating this as four separate cases? > > Also, will this go wrong if someone creates a resctrl group with '\n' > (i.e., a newline character) in the name? There is a check for this in rdtgroup_mkdir(). > >> + >> + Op-code can be one of the following: >> + :: >> + >> + = Update the assignment to match the flags >> + + Assign a new state >> + - Unassign a new state >> + _ Unassign all the states > > I can't remember whether I already asked this, but is "_" really > needed here? Asked twice: https://lore.kernel.org/lkml/ZiaRXrmDDjc194JI@xxxxxxxxxxxxxxx/ https://lore.kernel.org/lkml/ZiervIprcwoApAqw@xxxxxxxxxxxxxxx/ Answered: https://lore.kernel.org/lkml/4cd220cc-2e8e-4193-b01a-d3cd798c7118@xxxxxxx/ You seemed ok with answer then: https://lore.kernel.org/lkml/ZiffF93HM8bE3qo7@xxxxxxxxxxxxxxx/ > > Wouldn't it be the case that > > //*_ > > would mean just the same thing as > > //*=_ > > ...? (assuming the "*" = "all domains" convention already discussed) > > Maybe I'm missing something here. I believe have an explicit operator ("+", "=", or "-") simplifies parsing while providing an interface consistent with what users are already used to. Reinette
