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Diffstat (limited to 'static/unix-v10/man5/lnode.5')
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diff --git a/static/unix-v10/man5/lnode.5 b/static/unix-v10/man5/lnode.5 new file mode 100644 index 00000000..ea07da47 --- /dev/null +++ b/static/unix-v10/man5/lnode.5 @@ -0,0 +1,166 @@ +.TH LNODE 5 SHARE +.SH NAME +lnode \- kernel user shares structure +.SH SYNOPSIS +.B "#include <sys/lnode.h>" +.SH DESCRIPTION +The kernel +.I lnode +structure is used to maintain per-user shares while a user has processes running. +.I Lnodes +are installed by +.IR login (8) +via the +.IR limits (2) +system call when a new user logs into the system. +.I Dead +lnodes are removed by +.IR sharer (8) +when the last process for a user exits. +The layout as given in the include file is: +.PP +.nf +.ift .ta 1.1i 1.9i +.ifn .ta 24n 35n +/* + * Structure for active shares + */ + +typedef short uid_t; + +.ift .ta .3i 1.1i 1.9i +.ifn .ta 2n +10n +13n +struct lnode +{ + uid_t l_uid; /* real uid for owner of this node */ + u_short l_flags; /* (see below) */ + u_short l_shares; /* allocated shares */ + uid_t l_group; /* uid for this node's scheduling group */ + float l_usage; /* decaying accumulated costs */ + float l_charge; /* long term accumulated costs */ +}; + +/* + * Meaning of bits in l_flags + */ + +.ift .ta .6i 1.8i 2.4i +.ifn .ta +8n +11n +6n +#define \s-1ACTIVELNODE\s0 001 /* this lnode is on active list */ +#define \s-1LASTREF\s0 002 /* set for L_DEADLIM if last reference to this lnode */ +#define \s-1DEADGROUP\s0 004 /* group account is dead */ +#define \s-1CHNGDLIMITS\s0 020 /* this lnode's limits have changed */ +#define \s-1NOTSHARED\s0 040 /* this lnode does not get a share of the m/c */ +.DT +.fi +.PP +.I Lnodes +are grouped together in a tree. +At any level in the tree, +the share of resources allocated to an individual lnode is that +proportion of the group's resources +represented by the ratio of the lnode's shares +to the total shares of all the lnodes in the group. +The +.I l_group +field represents the +.I uid +of the group leader's lnode. +The top of the tree is represented by +.IR root 's +lnode, which is initialised at system boot time. +.PP +The +.SM LASTREF +bit in +.I l_flags +is set for the +.SM L_DEADLIM +request to the +.IR limits (2) +system call if the last process referencing the +.I lnode +has exited. +The +.SM DEADGROUP +bit is set if this +.I lnode +was the last one referencing it's group. +Dead groups are collected via the +.SM L_DEADGROUP +request to the +.IR limits (2) +system call. +.PP +The +.I l_charge +field is the long term accumulated charge for consumption of resources. +For group leaders, it represents the charge for the whole group. +The +.I l_usage +field is a number representing recent usage of resources, +and is used by the scheduler to determine current share of resources. +.SS kern_lnode +Each user's +.I lnode +is embedded in a larger structure to hold temporary values for use +by the scheduler, known as a +.IR kern_lnode . +The layout as given in the include file is: +.PP +.nf +.ift .ta 1.9i +.ifn .ta 28n +/* + * Kernel user share structure + */ + +typedef struct kern_lnode * KL_p; + +.ift .ta .3i 1.1i 1.9i +.ifn .ta 2n +13n +13n +struct kern_lnode +{ + KL_p kl_next; /* next in active list */ + KL_p kl_prev; /* prev in active list */ + KL_p kl_parent; /* group parent */ + KL_p kl_gnext; /* next in parent's group */ + KL_p kl_ghead; /* start of this group */ + struct lnode kl; /* user parameters (as above) */ + float kl_gshares; /* total shares for this group */ + float kl_eshare; /* effective share for this group */ + float kl_norms; /* share**2 for this lnode */ + float kl_usage; /* kl.l_usage / kl_norms */ + float kl_rate; /* active process rate for this lnode */ + float kl_temp; /* temporary for scheduler */ + float kl_spare; /* <spare> */ + u_long kl_cost; /* cost accumulating in current period */ + u_long kl_muse; /* memory pages used */ + u_short kl_refcount; /* processes attached to this lnode */ + u_short kl_children; /* lnodes attached to this lnode */ +}; +.DT +.fi +.PP +Every process has a pointer to its owner's +.I kern_lnode +called +.I p_lnode. +Every time a process incurs a clock tick, +the value +.I p_lnode\->kl_usage +multipied by +.I p_lnode\->kl_rate +is added to its scheduling priority in +.IR p_sharepri . +.I p_sharepri +is decayed by the clock by an amount depending on the process's +.I p_nice +value \(em the ``nicer'' the process, the slower the decay. +This value is copied into the low-level scheduler's priority in +.I p_pri +whenever the process is run in user space. +.SH "SEE ALSO" +limits(2), +share(5), +sharer(8). |