CLEANUP: tinfo: better align fields in thread_ctx

The introduction of buffer_wq[] in thread_ctx pushed a few fields around
and the cache line alignment is less satisfying. And more importantly, even
before this, all the lists in the local parts were 8-aligned, with the first
one split across two cache lines.

We can do better:
  - sched_profile_entry is not atomic at all, the data it points to is
    atomic so it doesn't need to be in the atomic-only region, and it can
    fill the 8-hole before the lists
  - the align(2*void) that was only before tasklets[] moves before all
    lists (and it's a nop for now)

This now makes the lists and buffer_wq[] start on a cache line boundary,
leaves 48 bytes after the lists before the atomic-only cache line, and
leaves a full cache line at the end for 128-alignment. This way we still
have plenty of room in both parts with better aligned fields.

diff --git a/include/haproxy/tinfo-t.h b/include/haproxy/tinfo-t.h
index 4ed78756afc6c2a9b67c09752c29557d65257a64..5564a70b5c8fa2951899422e90040fbe71a5b673 100644 (file)
--- a/include/haproxy/tinfo-t.h
+++ b/include/haproxy/tinfo-t.h
@@ -137,17 +137,19 @@ struct thread_ctx {
        uint8_t tl_class_mask;              /* bit mask of non-empty tasklets classes */
        uint8_t bufq_map;                   /* one bit per non-empty buffer_wq */
 
-       // 6 bytes hole here
+       // 2 bytes hole here
+       unsigned int nb_rhttp_conns;        /* count of current conns used for active reverse HTTP */
+       struct sched_activity *sched_profile_entry; /* profile entry in use by the current task/tasklet, only if sched_wake_date>0 */
+
+       ALWAYS_ALIGN(2*sizeof(void*));
+       struct list buffer_wq[DYNBUF_NBQ];  /* buffer waiters, 4 criticality-based queues */
        struct list pool_lru_head;          /* oldest objects in thread-local pool caches */
        struct list streams;                /* list of streams attached to this thread */
        struct list quic_conns;             /* list of active quic-conns attached to this thread */
        struct list quic_conns_clo;         /* list of closing quic-conns attached to this thread */
        struct list queued_checks;          /* checks waiting for a connection slot */
-       struct list buffer_wq[DYNBUF_NBQ];  /* buffer waiters, 4 criticality-based queues */
-       unsigned int nb_rhttp_conns;        /* count of current conns used for active reverse HTTP */
-
-       ALWAYS_ALIGN(2*sizeof(void*));
        struct list tasklets[TL_CLASSES];   /* tasklets (and/or tasks) to run, by class */
+       // around 48 bytes here for thread-local variables
 
        // third cache line here on 64 bits: accessed mostly using atomic ops
        ALWAYS_ALIGN(64);
@@ -161,7 +163,6 @@ struct thread_ctx {
 
        uint32_t sched_wake_date;           /* current task/tasklet's wake date or 0 */
        uint32_t sched_call_date;           /* current task/tasklet's call date (valid if sched_wake_date > 0) */
-       struct sched_activity *sched_profile_entry; /* profile entry in use by the current task/tasklet, only if sched_wake_date>0 */
 
        uint64_t prev_cpu_time;             /* previous per thread CPU time */
        uint64_t prev_mono_time;            /* previous system wide monotonic time  */
@@ -175,6 +176,7 @@ struct thread_ctx {
        unsigned long long out_bytes;           /* total #of bytes emitted */
        unsigned long long spliced_out_bytes;   /* total #of bytes emitted though a kernel pipe */
        struct buffer *thread_dump_buffer;      /* NULL out of dump, valid during a dump, 0x01 once done */
+       // around 64 bytes here for shared variables
 
        ALWAYS_ALIGN(128);
 };