Cleanup: Make memory barrier definitions consistent across kernels

We inherited membar_consumer() and membar_producer() from OpenSolaris,
but we had replaced membar_consumer() with Linux's smp_rmb() in
zfs_ioctl.c. The FreeBSD SPL consequently implemented a shim for the
Linux-only smp_rmb().

We reinstate membar_consumer() in platform independent code and fix the
FreeBSD SPL to implement membar_consumer() in a way analogous to Linux.

Reviewed-by: Konstantin Belousov <kib@FreeBSD.org>
Reviewed-by: Mateusz Guzik <mjguzik@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Neal Gompa <ngompa@datto.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13843
This commit is contained in:
Richard Yao 2022-09-13 19:59:33 -04:00 committed by GitHub
parent 8fdc229a9c
commit cf66e7e594
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4 changed files with 5 additions and 3 deletions

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@ -83,7 +83,6 @@
#define __printf(a, b) __printflike(a, b) #define __printf(a, b) __printflike(a, b)
#define barrier() __asm__ __volatile__("": : :"memory") #define barrier() __asm__ __volatile__("": : :"memory")
#define smp_rmb() rmb()
#define ___PASTE(a, b) a##b #define ___PASTE(a, b) a##b
#define __PASTE(a, b) ___PASTE(a, b) #define __PASTE(a, b) ___PASTE(a, b)

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@ -57,7 +57,8 @@ extern uint64_t atomic_cas_64(volatile uint64_t *target, uint64_t cmp,
uint64_t newval); uint64_t newval);
#endif #endif
#define membar_producer atomic_thread_fence_rel #define membar_consumer() atomic_thread_fence_acq()
#define membar_producer() atomic_thread_fence_rel()
static __inline uint32_t static __inline uint32_t
atomic_add_32_nv(volatile uint32_t *target, int32_t delta) atomic_add_32_nv(volatile uint32_t *target, int32_t delta)

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@ -44,7 +44,9 @@
#define zfs_totalhigh_pages totalhigh_pages #define zfs_totalhigh_pages totalhigh_pages
#endif #endif
#define membar_consumer() smp_rmb()
#define membar_producer() smp_wmb() #define membar_producer() smp_wmb()
#define physmem zfs_totalram_pages #define physmem zfs_totalram_pages
#define xcopyin(from, to, size) copy_from_user(to, from, size) #define xcopyin(from, to, size) copy_from_user(to, from, size)

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@ -7482,7 +7482,7 @@ zfsdev_get_state(minor_t minor, enum zfsdev_state_type which)
for (zs = zfsdev_state_list; zs != NULL; zs = zs->zs_next) { for (zs = zfsdev_state_list; zs != NULL; zs = zs->zs_next) {
if (zs->zs_minor == minor) { if (zs->zs_minor == minor) {
smp_rmb(); membar_consumer();
switch (which) { switch (which) {
case ZST_ONEXIT: case ZST_ONEXIT:
return (zs->zs_onexit); return (zs->zs_onexit);