mirror of https://gitee.com/openkylin/linux.git
df323337e5
The get_buffers() macro may provide one or two buffers to the caller. Those buffers are pre-allocated on init for each CPU. By default it allocates 2* 2 * MAX_PATH * POSSIBLE_CPU which equals 64KiB on a system with 4 CPUs or 1MiB with 64 CPUs and so on. Replace the per-CPU buffers with a common memory pool which is shared across all CPUs. The pool grows on demand and never shrinks. The pool starts with two (UP) or four (SMP) elements. By using this pool it is possible to request a buffer and keeping preemption enabled which avoids the hack in profile_transition(). It has been pointed out by Tetsuo Handa that GFP_KERNEL allocations for small amount of memory do not fail. In order not to have an endless retry, __GFP_RETRY_MAYFAIL is passed (so the memory allocation is not repeated until success) and retried once hoping that in the meantime a buffer has been returned to the pool. Since now NULL is possible all allocation paths check the buffer pointer and return -ENOMEM on failure. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: John Johansen <john.johansen@canonical.com> |
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| .. | ||
| include | ||
| .gitignore | ||
| Kconfig | ||
| Makefile | ||
| apparmorfs.c | ||
| audit.c | ||
| capability.c | ||
| crypto.c | ||
| domain.c | ||
| file.c | ||
| ipc.c | ||
| label.c | ||
| lib.c | ||
| lsm.c | ||
| match.c | ||
| mount.c | ||
| net.c | ||
| nulldfa.in | ||
| path.c | ||
| policy.c | ||
| policy_ns.c | ||
| policy_unpack.c | ||
| procattr.c | ||
| resource.c | ||
| secid.c | ||
| stacksplitdfa.in | ||
| task.c | ||