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    Subject[PATCH] BC: resource beancounters (v4) (added user memory)
    Core Resource Beancounters (BC) + kernel/user memory control.

    BC allows to account and control consumption
    of kernel resources used by group of processes.

    Draft UBC description on OpenVZ wiki can be found at

    The full BC patch set allows to control:
    - kernel memory. All the kernel objects allocatable
    on user demand should be accounted and limited
    for DoS protection.
    E.g. page tables, task structs, vmas etc.

    - virtual memory pages. BCs allow to
    limit a container to some amount of memory and
    introduces 2-level OOM killer taking into account
    container's consumption.
    pages shared between containers are correctly
    charged as fractions (tunable).

    - network buffers. These includes TCP/IP rcv/snd
    buffers, dgram snd buffers, unix, netlinks and
    other buffers.

    - minor resources accounted/limited by number:
    tasks, files, flocks, ptys, siginfo, pinned dcache
    mem, sockets, iptentries (for containers with
    virtualized networking)

    As the first step we want to propose for discussion
    the most complicated parts of resource management:
    kernel memory and virtual memory.
    The patch set to be sent provides core for BC and
    management of kernel memory only. Virtual memory
    management will be sent in a couple of days.

    The patches in these series are:
    introduce atomic_dec_and_lock_irqsave()

    Adds kernel/bc/Kconfig file with UBC options and
    includes it into arch Kconfigs

    Contains core functionality and interfaces of BC:
    find/create beancounter, initialization,
    charge/uncharge of resource, core objects' declarations.

    Contains code responsible for setting BC on task,
    it's inheriting and setting host context in interrupts.

    Task contains three beancounters:
    1. exec_bc - current context. all resources are charged
    to this beancounter.
    2. fork_bc - beancounter which is inherited by
    task's children on fork

    Patch adds system calls for BC management:
    1. sys_get_bcid - get current BC id
    2. sys_set_bcid - changes exec_ and fork_ BCs on current
    3. sys_set_bclimit - set limits for resources consumtions
    4. sys_get_bcstat - returns limits/usages/fails for BC

    Introduces BC_KMEMSIZE resource which accounts kernel
    objects allocated by task's request.

    Objects are accounted via struct page and slab objects.
    For the latter ones each slab contains a set of pointers
    corresponding object is charged to.

    Allocation charge rules:
    1. Pages - if allocation is performed with __GFP_BC flag - page
    is charged to current's exec_bc.
    2. Slabs - kmem_cache may be created with SLAB_BC flag - in this
    case each allocation is charged. Caches used by kmalloc are
    created with SLAB_BC | SLAB_BC_NOCHARGE flags. In this case
    only __GFP_BC allocations are charged.

    Adds SLAB_BC and __GFP_BC flags in appropriate places
    to cause charging/limiting of specified resources.

    Introduces new resource BC_LOCKEDPAGES for accounting
    of mlock-ed user pages.

    Places calls to BC core over the kernel to charge locked memory.

    This patch instroduces new resource - BC_PRIVVMPAGES.
    Privvmpages acointing is described in details in

    This patch intruduces small preparations for vmrss accounting
    to make reviewing simpler.

    This is the core of vmrss accounting.
    Pages are accounted in fractions and it is described in details in

    Calls to vmrss core code over the kernel to do accounting.

    Summary of changes from v3 patch set:

    * Added basic user pages accounting (lockedpages/privvmpages)
    * spell in Kconfig
    * Makefile reworked
    * union w/o name in struct page
    * bc_task_charge is void now
    * adjust minheld/maxheld splitted

    Summary of changes from v2 patch set:

    * introduced atomic_dec_and_lock_irqsave()
    * bc_adjust_held_minmax comment
    * added __must_check for bc_*charge* funcs
    * use hash_long() instead of own one
    * bc/Kconfig is sourced from init/Kconfig now
    * introduced bcid_t type with comment from Alan Cox
    * check for barrier <= limit in sys_set_bclimit()
    * removed (bc == NULL) checks
    * replaced memcpy in beancounter_findcrate with assignment
    * moved check 'if (mask & BC_ALLOC)' out of the lock
    * removed unnecessary memset()

    Summary of changes from v1 patch set:

    * CONFIG_BEANCOUNTERS is 'n' by default
    * fixed Kconfig includes in arches
    * removed hierarchical beancounters to simplify first patchset
    * removed unused 'private' pointer
    * removed unused EXPORTS
    * MAXVALUE redeclared as LONG_MAX
    * beancounter_findcreate clarification
    * renamed UBC -> BC, ub -> bc etc.
    * moved BC inheritance into copy_process
    * introduced reset_exec_bc() with proposed BUG_ON
    * removed task_bc beancounter (not used yet, for numproc)
    * fixed syscalls for sparc
    * added sys_get_bcstat(): return info that was in /proc
    * cond_syscall instead of #ifdefs

    Many thanks to Oleg Nesterov, Alan Cox, Matt Helsley and others
    for patch review and comments.

    Patch set is applicable to 2.6.18-rc5-mm1

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      Last update: 2006-09-05 17:01    [W:0.025 / U:80.736 seconds]
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