Eric W. Biederman 99f8955183 [PATCH] proc: don't lock task_structs indefinitely ...

Every inode in /proc holds a reference to a struct task_struct.  If a
directory or file is opened and remains open after the the task exits this
pinning continues.  With 8K stacks on a 32bit machine the amount pinned per
file descriptor is about 10K.

Normally I would figure a reasonable per user process limit is about 100
processes.  With 80 processes, with a 1000 file descriptors each I can trigger
the 00M killer on a 32bit kernel, because I have pinned about 800MB of useless
data.

This patch replaces the struct task_struct pointer with a pointer to a struct
task_ref which has a struct task_struct pointer.  The so the pinning of dead
tasks does not happen.

The code now has to contend with the fact that the task may now exit at any
time.  Which is a little but not muh more complicated.

With this change it takes about 1000 processes each opening up 1000 file
descriptors before I can trigger the OOM killer.  Much better.

[[email protected]: task_mmu small fixes]
Signed-off-by: Eric W. Biederman <[email protected]>
Cc: Trond Myklebust <[email protected]>
Cc: Paul Jackson <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Albert Cahalan <[email protected]>
Signed-off-by: Prasanna Meda <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

2006-06-26 09:58:25 -07:00

..

bootmem.c

…

fadvise.c

…

filemap_xip.c

…

filemap.c

[PATCH] readahead: backoff on I/O error

2006-06-25 10:01:17 -07:00

filemap.h

[PATCH] Prepare for __copy_from_user_inatomic to not zero missed bytes

2006-06-25 10:01:09 -07:00

fremap.c

[PATCH] fix update_mmu_cache in fremap.c

2006-06-23 07:42:52 -07:00

highmem.c

…

hugetlb.c

[PATCH] tightening hugetlb strict accounting

2006-06-23 07:42:48 -07:00

internal.h

…

Kconfig

[PATCH] Swapless page migration: modify core logic

2006-06-23 07:42:50 -07:00

madvise.c

…

Makefile

…

memory_hotplug.c

[PATCH] update vm_total_pages at memory hotadd

2006-06-23 07:42:52 -07:00

memory.c

[PATCH] add page_mkwrite() vm_operations method

2006-06-23 07:42:51 -07:00

mempolicy.c

[PATCH] proc: don't lock task_structs indefinitely

2006-06-26 09:58:25 -07:00

mempool.c

…

migrate.c

[PATCH] Allow migration of mlocked pages

2006-06-25 10:00:55 -07:00

mincore.c

…

mlock.c

…

mmap.c

[PATCH] add page_mkwrite() vm_operations method

2006-06-23 07:42:51 -07:00

mmzone.c

…

mprotect.c

[PATCH] add page_mkwrite() vm_operations method

2006-06-23 07:42:51 -07:00

mremap.c

…

msync.c

[PATCH] Kill PF_SYNCWRITE flag

2006-06-23 17:10:39 +02:00

nommu.c

…

oom_kill.c

[PATCH] mm: fix typos in comments in mm/oom_kill.c

2006-06-23 07:42:47 -07:00

page_alloc.c

[PATCH] cpuset: remove extra cpuset_zone_allowed check in __alloc_pages

2006-06-25 10:01:08 -07:00

page_io.c

…

page-writeback.c

[PATCH] writeback: fix range handling

2006-06-23 07:42:49 -07:00

pdflush.c

[PATCH] pdflush: handle resume wakeups

2006-06-25 10:01:06 -07:00

prio_tree.c

…

readahead.c

[PATCH] kernel-doc: mm/readhead fixup

2006-06-25 10:01:10 -07:00

rmap.c

[PATCH] Allow migration of mlocked pages

2006-06-25 10:00:55 -07:00

shmem.c

Merge branch 'master' of /home/trondmy/kernel/linux-2.6/

2006-06-24 13:07:53 -04:00

slab.c

[PATCH] slab: kmalloc, kzalloc comments cleanup and fix

2006-06-23 07:42:52 -07:00

slob.c

[PATCH] mm/slob.c: for_each_possible_cpu(), not NR_CPUS

2006-04-19 09:13:49 -07:00

sparse.c

[PATCH] sparsemem: record nid during memory present

2006-06-23 07:42:51 -07:00

swap_state.c

…

swap.c

[PATCH] core: use list_move()

2006-06-26 09:58:17 -07:00

swapfile.c

[PATCH] read_mapping_page for address space

2006-06-23 07:43:02 -07:00

thrash.c

…

tiny-shmem.c

…

truncate.c

[PATCH] Remove semi-softlockup from invalidate_mapping_pages

2006-06-23 07:43:07 -07:00

util.c

…

vmalloc.c

[PATCH] mm: introduce remap_vmalloc_range()

2006-06-23 07:42:49 -07:00

vmscan.c

[PATCH] initialise total_memory() earlier

2006-06-23 07:42:52 -07:00