mirror of
https://github.com/koverstreet/bcachefs-tools.git
synced 2025-02-23 00:00:02 +03:00
f5baaf48e3
This moves the Rust sources out of rust_src/ and into the top level. Running the bcachefs executable out of the development tree is now: $ ./target/release/bcachefs command or $ cargo run --profile release -- command instead of "./bcachefs command". Building and installing is still: $ make && make install Signed-off-by: Thomas Bertschinger <tahbertschinger@gmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
38 lines
1.1 KiB
C
38 lines
1.1 KiB
C
#include <pthread.h>
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#include "linux/preempt.h"
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/*
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* In userspace, pthreads are preemptible and can migrate CPUs at any time.
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*
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* In the kernel, preempt_disable() logic essentially guarantees that a marked
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* critical section owns its CPU for the relevant block. This is necessary for
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* various code paths, critically including the percpu system as it allows for
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* non-atomic reads and writes to CPU-local data structures.
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*
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* The high performance userspace equivalent would be to use thread local
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* storage to replace percpu data, but that would be complicated. It should be
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* correct to instead guarantee mutual exclusion for the critical sections.
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*/
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static pthread_mutex_t preempt_lock;
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__attribute__((constructor))
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static void preempt_init(void) {
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pthread_mutexattr_t attr;
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pthread_mutexattr_init(&attr);
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pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
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pthread_mutex_init(&preempt_lock, &attr);
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pthread_mutexattr_destroy(&attr);
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}
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void preempt_disable(void)
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{
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pthread_mutex_lock(&preempt_lock);
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}
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void preempt_enable(void)
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{
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pthread_mutex_unlock(&preempt_lock);
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}
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