https://github.com/torvalds/linux
Revision f36963c9d3f6f415732710da3acdd8608a9fa0e5 authored by Rusty Russell on 08 May 2015, 17:44:13 UTC, committed by Rusty Russell on 28 May 2015, 01:35:20 UTC
da91309e0a7e (cpumask: Utility function to set n'th cpu...) created a genuinely weird function. I never saw it before, it went through DaveM. (He only does this to make us other maintainers feel better about our own mistakes.) cpumask_set_cpu_local_first's purpose is say "I need to spread things across N online cpus, choose the ones on this numa node first"; you call it in a loop. It can fail. One of the two callers ignores this, the other aborts and fails the device open. It can fail in two ways: allocating the off-stack cpumask, or through a convoluted codepath which AFAICT can only occur if cpu_online_mask changes. Which shouldn't happen, because if cpu_online_mask can change while you call this, it could return a now-offline cpu anyway. It contains a nonsensical test "!cpumask_of_node(numa_node)". This was drawn to my attention by Geert, who said this causes a warning on Sparc. It sets a single bit in a cpumask instead of returning a cpu number, because that's what the callers want. It could be made more efficient by passing the previous cpu rather than an index, but that would be more invasive to the callers. Fixes: da91309e0a7e8966d916a74cce42ed170fde06bf Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (then rebased) Tested-by: Amir Vadai <amirv@mellanox.com> Acked-by: Amir Vadai <amirv@mellanox.com> Acked-by: David S. Miller <davem@davemloft.net>
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Tip revision: f36963c9d3f6f415732710da3acdd8608a9fa0e5 authored by Rusty Russell on 08 May 2015, 17:44:13 UTC
cpumask_set_cpu_local_first => cpumask_local_spread, lament
cpumask_set_cpu_local_first => cpumask_local_spread, lament
Tip revision: f36963c
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arch | ||
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crypto | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
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net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
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.gitignore | -rw-r--r-- | 1.2 KB |
.mailmap | -rw-r--r-- | 4.9 KB |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 94.5 KB |
Kbuild | -rw-r--r-- | 2.1 KB |
Kconfig | -rw-r--r-- | 252 bytes |
MAINTAINERS | -rw-r--r-- | 302.2 KB |
Makefile | -rw-r--r-- | 53.1 KB |
README | -rw-r--r-- | 18.2 KB |
REPORTING-BUGS | -rw-r--r-- | 7.3 KB |
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