Return to lnode.5 CVS log

Up to [Research Unix] / researchv10dc / man / manx

Annotation of researchv10dc/man/manx/lnode.5, revision 1.1

1.1     ! root        1: .TH LNODE 5 SHARE
        !             2: .SH NAME
        !             3: lnode \- kernel user shares structure
        !             4: .SH SYNOPSIS
        !             5: .B "#include <sys/lnode.h>"
        !             6: .SH DESCRIPTION
        !             7: The kernel
        !             8: .I lnode
        !             9: structure is used to maintain per-user shares while a user has processes running.
        !            10: .I Lnodes
        !            11: are installed by
        !            12: .IR login (8)
        !            13: via the 
        !            14: .IR limits (2)
        !            15: system call when a new user logs into the system.
        !            16: .I Dead
        !            17: lnodes are removed by 
        !            18: .IR sharer (8)
        !            19: when the last process for a user exits.
        !            20: The layout as given in the include file is:
        !            21: .PP
        !            22: .nf
        !            23: .ift .ta 1.1i 1.9i
        !            24: .ifn .ta 24n 35n
        !            25: /*
        !            26:  * Structure for active shares
        !            27:  */
        !            28: 
        !            29: typedef short  uid_t;
        !            30: 
        !            31: .ift .ta .3i 1.1i 1.9i
        !            32: .ifn .ta 2n +10n +13n
        !            33: struct lnode
        !            34: {
        !            35:        uid_t   l_uid;  /* real uid for owner of this node */
        !            36:        u_short l_flags;        /* (see below) */
        !            37:        u_short l_shares;       /* allocated shares */
        !            38:        uid_t   l_group;        /* uid for this node's scheduling group */
        !            39:        float   l_usage;        /* decaying accumulated costs */
        !            40:        float   l_charge;       /* long term accumulated costs */
        !            41: };
        !            42: 
        !            43: /*
        !            44:  * Meaning of bits in l_flags
        !            45:  */
        !            46: 
        !            47: .ift .ta .6i 1.8i 2.4i
        !            48: .ifn .ta +8n +11n +6n
        !            49: #define        \s-1ACTIVELNODE\s0      001     /* this lnode is on active list */
        !            50: #define        \s-1LASTREF\s0  002     /* set for L_DEADLIM if last reference to this lnode */
        !            51: #define        \s-1DEADGROUP\s0        004     /* group account is dead */
        !            52: #define        \s-1CHNGDLIMITS\s0      020     /* this lnode's limits have changed */
        !            53: #define        \s-1NOTSHARED\s0        040     /* this lnode does not get a share of the m/c */
        !            54: .DT
        !            55: .fi
        !            56: .PP
        !            57: .I Lnodes
        !            58: are grouped together in a tree.
        !            59: At any level in the tree,
        !            60: the share of resources allocated to an individual lnode is that 
        !            61: proportion of the group's resources
        !            62: represented by the ratio of the lnode's shares
        !            63: to the total shares of all the lnodes in the group.
        !            64: The 
        !            65: .I l_group
        !            66: field represents the 
        !            67: .I uid
        !            68: of the group leader's lnode.
        !            69: The top of the tree is represented by
        !            70: .IR root 's
        !            71: lnode, which is initialised at system boot time.
        !            72: .PP
        !            73: The
        !            74: .SM LASTREF
        !            75: bit in
        !            76: .I l_flags
        !            77: is set for the 
        !            78: .SM L_DEADLIM
        !            79: request to the
        !            80: .IR limits (2)
        !            81: system call if the last process referencing the 
        !            82: .I lnode 
        !            83: has exited.
        !            84: The
        !            85: .SM DEADGROUP
        !            86: bit is set if this
        !            87: .I lnode
        !            88: was the last one referencing it's group.
        !            89: Dead groups are collected via the
        !            90: .SM L_DEADGROUP
        !            91: request to the
        !            92: .IR limits (2)
        !            93: system call.
        !            94: .PP
        !            95: The
        !            96: .I l_charge
        !            97: field is the long term accumulated charge for consumption of resources.
        !            98: For group leaders, it represents the charge for the whole group.
        !            99: The 
        !           100: .I l_usage
        !           101: field is a number representing recent usage of resources,
        !           102: and is used by the scheduler to determine current share of resources.
        !           103: .SS kern_lnode
        !           104: Each user's
        !           105: .I lnode
        !           106: is embedded in a larger structure to hold temporary values for use
        !           107: by the scheduler, known as a
        !           108: .IR kern_lnode .
        !           109: The layout as given in the include file is:
        !           110: .PP
        !           111: .nf
        !           112: .ift .ta 1.9i
        !           113: .ifn .ta 28n
        !           114: /*
        !           115:  * Kernel user share structure
        !           116:  */
        !           117: 
        !           118: typedef struct kern_lnode *    KL_p;
        !           119: 
        !           120: .ift .ta .3i 1.1i 1.9i
        !           121: .ifn .ta 2n +13n +13n
        !           122: struct kern_lnode
        !           123: {
        !           124:        KL_p    kl_next;        /* next in active list */
        !           125:        KL_p    kl_prev;        /* prev in active list */
        !           126:        KL_p    kl_parent;      /* group parent */
        !           127:        KL_p    kl_gnext;       /* next in parent's group */
        !           128:        KL_p    kl_ghead;       /* start of this group */
        !           129:        struct lnode    kl;     /* user parameters (as above) */
        !           130:        float   kl_gshares;     /* total shares for this group */
        !           131:        float   kl_eshare;      /* effective share for this group */
        !           132:        float   kl_norms;       /* share**2 for this lnode */
        !           133:        float   kl_usage;       /* kl.l_usage / kl_norms */
        !           134:        float   kl_rate;        /* active process rate for this lnode */
        !           135:        float   kl_temp;        /* temporary for scheduler */
        !           136:        float   kl_spare;       /* <spare> */
        !           137:        u_long  kl_cost;        /* cost accumulating in current period */
        !           138:        u_long  kl_muse;        /* memory pages used */
        !           139:        u_short kl_refcount;    /* processes attached to this lnode */
        !           140:        u_short kl_children;    /* lnodes attached to this lnode */
        !           141: };
        !           142: .DT
        !           143: .fi
        !           144: .PP
        !           145: Every process has a pointer to its owner's
        !           146: .I kern_lnode
        !           147: called
        !           148: .I p_lnode.
        !           149: Every time a process incurs a clock tick,
        !           150: the value
        !           151: .I p_lnode\->kl_usage
        !           152: multipied by
        !           153: .I p_lnode\->kl_rate
        !           154: is added to its scheduling priority in
        !           155: .IR p_sharepri .
        !           156: .I p_sharepri
        !           157: is decayed by the clock by an amount depending on the process's
        !           158: .I p_nice
        !           159: value \(em the ``nicer'' the process, the slower the decay.
        !           160: This value is copied into the low-level scheduler's priority in
        !           161: .I p_pri
        !           162: whenever the process is run in user space.
        !           163: .SH "SEE ALSO"
        !           164: limits(2),
        !           165: share(5),
        !           166: sharer(8).

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.