When the dehugify functionality was retired in an previous commit, a
dehugify-related function and global variable in a test was
accidentally left in-place causing builds that add -Werror to CFLAGS
to fail.
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.
When hugepage is enabled and PAGESIZE is large, the test could
ask for a stack size larger than user limit. Allocating the
memory instead can avoid the failure.
Closes: #2408
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>
The maximum allowed value for `nflush_batch` is
`CACHE_BIN_NFLUSH_BATCH_MAX`. However, `tcache_bin_flush_impl_small`
could potentially declare an array of `emap_batch_lookup_result_t`
of size `CACHE_BIN_NFLUSH_BATCH_MAX + 1`. leads to a `VARIABLE_ARRAY`
assertion failure, observed when `tcache_nslots_small_max` is
configured to 2048. This patch ensures the array size does not exceed
the allowed maximum.
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>
See tikv/jemallocator#108.
In a summary, test on `strerror_r` can fail due to reasons other
than `strerror_r` itself, so add an additional test to determine
the failure is expected.
Signed-off-by: Jay Lee <BusyJayLee@gmail.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.
Implementation inspired by idea described in "Beyond malloc efficiency
to fleet efficiency: a hugepage-aware memory allocator" paper [1].
Primary idea is to track maximum number (peak) of active pages in use
with sliding window and then use this number to decide how many dirty
pages we would like to keep.
We are trying to estimate maximum amount of active memory we'll need in
the near future. We do so by projecting future active memory demand
(based on peak active memory usage we observed in the past within
sliding window) and adding slack on top of it (an overhead is reasonable
to have in exchange of higher hugepages coverage). When peak demand
tracking is off, projection of future active memory is active memory we
are having right now.
Estimation is essentially the same as `nactive_max * (1 + dirty_mult)`.
Peak demand purging algorithm controlled by two config options. Option
`hpa_peak_demand_window_ms` controls duration of sliding window we track
maximum active memory usage in and option `hpa_dirty_mult` controls
amount of slack we are allowed to have as a percent from maximum active
memory usage. By default `hpa_peak_demand_window_ms == 0` now and we
have same behaviour (ratio based purging) that we had before this
commit.
[1]: https://storage.googleapis.com/gweb-research2023-media/pubtools/6170.pdf
Add opt.process_madvise_max_batch which determines if process_madvise is enabled
(non-zero) and the max # of regions in each batch. Added another limiting
factor which is the space to reserve on stack, which results in the max batch of
128.
