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| author | Jason Evans <jasone@canonware.com> | 2017-02-09 21:00:59 (GMT) |
|---|---|---|
| committer | Jason Evans <jasone@canonware.com> | 2017-02-10 22:06:31 (GMT) |
| commit | cd2501efd621b76f799d9f264385b348c6e6678d (patch) | |
| tree | 3e564742c86ce52d42792878838c295430392624 | |
| parent | 6b8ef771a9de9318964f8b5b7cff5ea3958f0294 (diff) | |
| download | jemalloc-cd2501efd621b76f799d9f264385b348c6e6678d.zip jemalloc-cd2501efd621b76f799d9f264385b348c6e6678d.tar.gz jemalloc-cd2501efd621b76f799d9f264385b348c6e6678d.tar.bz2 | |
Fix extent_alloc_dss() regression.
Fix extent_alloc_dss() to account for bytes that are not a multiple of
the page size. This regression was introduced by
577d4572b0821a15e5370f9bf566d884b7cf707c (Make dss operations
lockless.), which was first released in 4.3.0.
| -rw-r--r-- | src/extent_dss.c | 48 |
1 files changed, 29 insertions, 19 deletions
diff --git a/src/extent_dss.c b/src/extent_dss.c index 0b4e1fe..5082571 100644 --- a/src/extent_dss.c +++ b/src/extent_dss.c @@ -121,35 +121,45 @@ extent_alloc_dss(tsdn_t *tsdn, arena_t *arena, void *new_addr, size_t size, * malloc. */ while (true) { - void *ret, *max_cur, *gap_addr, *dss_next, *dss_prev; - size_t gap_size; - intptr_t incr; - - max_cur = extent_dss_max_update(new_addr); + void *max_cur = extent_dss_max_update(new_addr); if (max_cur == NULL) { goto label_oom; } /* - * Compute how much gap space (if any) is necessary to - * satisfy alignment. This space can be recycled for - * later use. + * Compute how much page-aligned gap space (if any) is + * necessary to satisfy alignment. This space can be + * recycled for later use. */ - gap_addr = (void *)(PAGE_CEILING((uintptr_t)max_cur)); - ret = (void *)ALIGNMENT_CEILING((uintptr_t)gap_addr, - PAGE_CEILING(alignment)); - gap_size = (uintptr_t)ret - (uintptr_t)gap_addr; - if (gap_size != 0) { - extent_init(gap, arena, gap_addr, gap_size, - gap_size, arena_extent_sn_next(arena), + void *gap_addr_page = (void *)(PAGE_CEILING( + (uintptr_t)max_cur)); + void *ret = (void *)ALIGNMENT_CEILING( + (uintptr_t)gap_addr_page, alignment); + size_t gap_size_page = (uintptr_t)ret - + (uintptr_t)gap_addr_page; + if (gap_size_page != 0) { + extent_init(gap, arena, gap_addr_page, + gap_size_page, gap_size_page, + arena_extent_sn_next(arena), extent_state_active, false, true, false); } - dss_next = (void *)((uintptr_t)ret + size); + /* + * Compute the address just past the end of the desired + * allocation space. + */ + void *dss_next = (void *)((uintptr_t)ret + size); if ((uintptr_t)ret < (uintptr_t)max_cur || (uintptr_t)dss_next < (uintptr_t)max_cur) { goto label_oom; /* Wrap-around. */ } - incr = gap_size + size; + /* Compute the increment, including subpage bytes. */ + void *gap_addr_subpage = max_cur; + size_t gap_size_subpage = (uintptr_t)ret - + (uintptr_t)gap_addr_subpage; + intptr_t incr = gap_size_subpage + size; + + assert((uintptr_t)max_cur + incr == (uintptr_t)ret + + size); /* * Optimistically update dss_max, and roll back below if @@ -162,10 +172,10 @@ extent_alloc_dss(tsdn_t *tsdn, arena_t *arena, void *new_addr, size_t size, } /* Try to allocate. */ - dss_prev = extent_dss_sbrk(incr); + void *dss_prev = extent_dss_sbrk(incr); if (dss_prev == max_cur) { /* Success. */ - if (gap_size != 0) { + if (gap_size_page != 0) { extent_dalloc_gap(tsdn, arena, gap); } else { extent_dalloc(tsdn, arena, gap); |