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| author | Jeff Roberson <jeff@FreeBSD.org> | 2019-10-15 03:35:11 +0000 |
|---|---|---|
| committer | Jeff Roberson <jeff@FreeBSD.org> | 2019-10-15 03:35:11 +0000 |
| commit | 63e9755548e4feebf798686ab8bce0cdaaaf7b46 (patch) | |
| tree | 73004f9ecd43d157304327e6d0feb4ddf93012af /sys/kern/uipc_shm.c | |
| parent | f44e7436797617b6c6a42a280befb312f1ebf50f (diff) | |
| download | src-63e9755548e4feebf798686ab8bce0cdaaaf7b46.tar.gz src-63e9755548e4feebf798686ab8bce0cdaaaf7b46.zip | |
(1/6) Replace busy checks with acquires where it is trival to do so.
This is the first in a series of patches that promotes the page busy field
to a first class lock that no longer requires the object lock for
consistency.
Reviewed by: kib, markj
Tested by: pho
Sponsored by: Netflix, Intel
Differential Revision: https://reviews.freebsd.org/D21548
Notes
Notes:
svn path=/head/; revision=353535
Diffstat (limited to 'sys/kern/uipc_shm.c')
| -rw-r--r-- | sys/kern/uipc_shm.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/sys/kern/uipc_shm.c b/sys/kern/uipc_shm.c index e0c6be1f0fab..b0aaac0659a5 100644 --- a/sys/kern/uipc_shm.c +++ b/sys/kern/uipc_shm.c @@ -457,10 +457,9 @@ shm_dotruncate_locked(struct shmfd *shmfd, off_t length, void *rl_cookie) if (base != 0) { idx = OFF_TO_IDX(length); retry: - m = vm_page_lookup(object, idx); + m = vm_page_grab(object, idx, VM_ALLOC_NOCREAT); if (m != NULL) { - if (vm_page_sleep_if_busy(m, "shmtrc")) - goto retry; + MPASS(m->valid == VM_PAGE_BITS_ALL); } else if (vm_pager_has_page(object, idx, NULL, NULL)) { m = vm_page_alloc(object, idx, VM_ALLOC_NORMAL | VM_ALLOC_WAITFAIL); @@ -478,7 +477,6 @@ retry: * as an access. */ vm_page_launder(m); - vm_page_xunbusy(m); } else { vm_page_free(m); VM_OBJECT_WUNLOCK(object); @@ -490,6 +488,7 @@ retry: KASSERT(m->valid == VM_PAGE_BITS_ALL, ("shm_dotruncate: page %p is invalid", m)); vm_page_dirty(m); + vm_page_xunbusy(m); vm_pager_page_unswapped(m); } } |