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| author | Andrew Morton <akpm@linux-foundation.org> | 2009-04-09 17:50:37 +0200 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2009-04-09 02:20:37 +0200 |
| commit | 6b44003e5ca66a3fffeb5bc90f40ada2c4340896 (patch) | |
| tree | d9dce0a39b5e66d8e760344a51ffb6de9594cd2f /drivers/ata/sata_nv.c | |
| parent | kthread: move sched-realeted initialization from kthreadd context (diff) | |
| download | linux-6b44003e5ca66a3fffeb5bc90f40ada2c4340896.tar.xz linux-6b44003e5ca66a3fffeb5bc90f40ada2c4340896.zip | |
work_on_cpu(): rewrite it to create a kernel thread on demand
Impact: circular locking bugfix
The various implemetnations and proposed implemetnations of work_on_cpu()
are vulnerable to various deadlocks because they all used queues of some
form.
Unrelated pieces of kernel code thus gained dependencies wherein if one
work_on_cpu() caller holds a lock which some other work_on_cpu() callback
also takes, the kernel could rarely deadlock.
Fix this by creating a short-lived kernel thread for each work_on_cpu()
invokation.
This is not terribly fast, but the only current caller of work_on_cpu() is
pci_call_probe().
It would be nice to find some other way of doing the node-local
allocations in the PCI probe code so that we can zap work_on_cpu()
altogether. The code there is rather nasty. I can't think of anything
simple at this time...
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/ata/sata_nv.c')
0 files changed, 0 insertions, 0 deletions