While undocumented, the prctl system call will set errno to ENOMEM
when passed NULL as an address. Under that condition, an assertion
that check for EINVAL as the only possible errno value will fail. To
avoid the assertion failure, this change skips the call to os_page_id
when address is NULL. NULL can only occur after mmap fails in which
case there is no mapping to name.
The address of the local variable created_threads is a different
location than the data it points to. Incorrectly treating these
values as being the same can cause out-of-bounds writes to the stack.
Closes: facebook/jemalloc#59
This change replaces direct comparisons of Pthread thread IDs with
calls to pthread_equal. Directly comparing thread IDs is neither
portable nor reliable since a thread ID is defined as an opaque type
that can be implemented using a structure.
The static inline definition made more sense when these functions just
dispatched to a syscall wrapper. Since they acquired a retry loop, a
non-inline definition makes more sense.
Giving the advice MADV_DONTNEED to a range of virtual memory backed by
a transparent huge page already causes that range of virtual memory to
become backed by regular pages.
any future changes to the underlying data type for bin sizes
(such as upgrading from `uint16_t` to `uint32_t`) can be achieved
by modifying only the `cache_bin_sz_t` definition.
Signed-off-by: Xin Yang <yangxin.dev@bytedance.com>
in the dirty ecache has been limited. This patch was tested with real
workloads using ClickHouse (Clickbench Q35) on a system with 2x240 vCPUs.
The results showed a 2X in query per second (QPS) performance and
a reduction in page faults to 29% of the previous rate. Additionally,
microbenchmark testing involved 256 memory reallocations resizing
from 4KB to 16KB in one arena, which demonstrated a 5X performance
improvement.
Signed-off-by: Jiebin Sun <jiebin.sun@intel.com>
If jemalloc is linked into a shared library, the RTLD_NEXT dlsym call
may fail since RTLD_NEXT is only specified to search all objects after
the current one in the loading order, and the pthread library may be
earlier in the load order. Instead of failing immediately, attempt one
more time to find pthread_create via RTLD_GLOBAL.
Errors cascading from this were observed on FreeBSD 14.1.
