project-base/server-skynet-source-3rd-jemalloc
2
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Optimizing TSD and thread cache layout.

Browse Source 
1) Re-organize TSD so that frequently accessed fields are closer to the
beginning and more compact.  Assuming 64-bit, the first 2.5 cachelines now
contains everything needed on tcache fast path, expect the tcache struct itself.

2) Re-organize tcache and tbins.  Take lg_fill_div out of tbin, and reduce tbin
to 24 bytes (down from 32). Split tbins into tbins_small and tbins_large, and
place tbins_small close to the beginning.
This commit is contained in:
Qi Wang
2017-04-06 12:35:22 -07:00
committed by Qi Wang
parent 4dec507546
commit 36bd90b962
10 changed files with 189 additions and 103 deletions
Download Patch File Download Diff File Expand all files Collapse all files

30
include/jemalloc/internal/tcache_structs.h
View File

@@ -10,10 +10,14 @@ struct tcache_bin_info_s {
};
struct tcache_bin_s {
low_water_t low_water; /* Min # cached since last GC. */
uint32_t ncached; /* # of cached objects. */
/*
* ncached and stats are both modified frequently. Let's keep them
* close so that they have a higher chance of being on the same
* cacheline, thus less write-backs.
*/
tcache_bin_stats_t tstats;
int low_water; /* Min # cached since last GC. */
unsigned lg_fill_div; /* Fill (ncached_max >> lg_fill_div). */
unsigned ncached; /* # of cached objects. */
/*
* To make use of adjacent cacheline prefetch, the items in the avail
* stack goes to higher address for newer allocations. avail points
@@ -25,11 +29,9 @@ struct tcache_bin_s {
};
struct tcache_s {
ql_elm(tcache_t) link; /* Used for aggregating stats. */
/* Data accessed frequently first: prof, ticker and small bins. */
uint64_t prof_accumbytes;/* Cleared after arena_prof_accum(). */
ticker_t gc_ticker; /* Drives incremental GC. */
szind_t next_gc_bin; /* Next bin to GC. */
arena_t *arena; /* Associated arena. */
/*
* The pointer stacks associated with tbins follow as a contiguous
* array. During tcache initialization, the avail pointer in each
@@ -37,9 +39,21 @@ struct tcache_s {
* this array.
*/
#ifdef JEMALLOC_TCACHE
tcache_bin_t tbins[NSIZES];
tcache_bin_t tbins_small[NBINS];
#else
tcache_bin_t tbins[0];
tcache_bin_t tbins_small[0];
#endif
/* Data accessed less often below. */
ql_elm(tcache_t) link; /* Used for aggregating stats. */
arena_t *arena; /* Associated arena. */
szind_t next_gc_bin; /* Next bin to GC. */
#ifdef JEMALLOC_TCACHE
/* For small bins, fill (ncached_max >> lg_fill_div). */
uint8_t lg_fill_div[NBINS];
tcache_bin_t tbins_large[NSIZES-NBINS];
#else
uint8_t lg_fill_div[0];
tcache_bin_t tbins_large[0];
#endif
};