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varnish-cache
Commit 867743f0 authored by Poul-Henning Kamp's avatar Poul-Henning Kamp
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Split rushing of waiting list into two stages: 1 get the req's to be rushed 

under the oh->mtx.  2 rush them out of the mtx.
parent 0895d2e6
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Showing with 68 additions and 41 deletions
bin/varnishd/cache/cache_hash.c
View file @ 867743f0
......@@ -57,15 +57,21 @@
#include "cache.h"
#include "hash/hash_slinger.h"
#include "vsha256.h"
#include "vtim.h"
struct rush {
unsigned magic;
#define RUSH_MAGIC 0xa1af5f01
VTAILQ_HEAD(,req) reqs;
};
static const struct hash_slinger *hash;
static struct objhead *private_oh;
static void hsh_rush(struct worker *wrk, struct objhead *oh);
static void hsh_rush1(struct worker *, struct objhead *, struct rush *, int);
static void hsh_rush2(struct worker *, struct rush *);
/*---------------------------------------------------------------------*/
......@@ -258,6 +264,7 @@ HSH_Insert(struct worker *wrk, const void *digest, struct objcore *oc,
struct ban *ban)
{
struct objhead *oh;
struct rush rush;
CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
AN(digest);
......@@ -266,6 +273,7 @@ HSH_Insert(struct worker *wrk, const void *digest, struct objcore *oc,
AN(oc->flags & OC_F_BUSY);
AZ(oc->flags & OC_F_PRIVATE);
assert(oc->refcnt == 1);
INIT_OBJ(&rush, RUSH_MAGIC);
hsh_prealloc(wrk);
......@@ -293,8 +301,9 @@ HSH_Insert(struct worker *wrk, const void *digest, struct objcore *oc,
VTAILQ_INSERT_HEAD(&oh->objcs, oc, hsh_list);
oc->flags &= ~OC_F_BUSY;
if (!VTAILQ_EMPTY(&oh->waitinglist))
hsh_rush(wrk, oh);
hsh_rush1(wrk, oh, &rush, 0);
Lck_Unlock(&oh->mtx);
hsh_rush2(wrk, &rush);
}
/*---------------------------------------------------------------------
......@@ -495,19 +504,21 @@ HSH_Lookup(struct req *req, struct objcore **ocp, struct objcore **bocp,
}
/*---------------------------------------------------------------------
* Pick the req's we are going to rush from the waiting list
*/
static void
hsh_rush(struct worker *wrk, struct objhead *oh)
hsh_rush1(struct worker *wrk, struct objhead *oh, struct rush *r, int all)
{
unsigned u;
struct req *req;
struct sess *sp;
CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
CHECK_OBJ_NOTNULL(oh, OBJHEAD_MAGIC);
CHECK_OBJ_NOTNULL(r, RUSH_MAGIC);
VTAILQ_INIT(&r->reqs);
Lck_AssertHeld(&oh->mtx);
for (u = 0; u < cache_param->rush_exponent; u++) {
for (u = 0; u < cache_param->rush_exponent || all; u++) {
req = VTAILQ_FIRST(&oh->waitinglist);
if (req == NULL)
break;
......@@ -515,32 +526,42 @@ hsh_rush(struct worker *wrk, struct objhead *oh)
wrk->stats->busy_wakeup++;
AZ(req->wrk);
VTAILQ_REMOVE(&oh->waitinglist, req, w_list);
VTAILQ_INSERT_TAIL(&r->reqs, req, w_list);
}
}
/*---------------------------------------------------------------------
* Rush req's that came from waiting list.
*/
static void
hsh_rush2(struct worker *wrk, struct rush *r)
{
struct req *req;
struct sess *sp;
CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
CHECK_OBJ_NOTNULL(r, RUSH_MAGIC);
while(!VTAILQ_EMPTY(&r->reqs)) {
req = VTAILQ_FIRST(&r->reqs);
CHECK_OBJ_NOTNULL(req, REQ_MAGIC);
VTAILQ_REMOVE(&r->reqs, req, w_list);
DSL(DBG_WAITINGLIST, req->vsl->wid, "off waiting list");
if (SES_Reschedule_Req(req)) {
/*
* In case of overloads, we ditch the entire
* waiting list.
*/
wrk->stats->busy_wakeup--;
while (1) {
wrk->stats->busy_killed++;
AN (req->vcl);
VCL_Rel(&req->vcl);
sp = req->sp;
CHECK_OBJ_NOTNULL(sp, SESS_MAGIC);
CNT_AcctLogCharge(wrk->stats, req);
Req_Release(req);
SES_Delete(sp, SC_OVERLOAD, NAN);
req = VTAILQ_FIRST(&oh->waitinglist);
if (req == NULL)
break;
CHECK_OBJ_NOTNULL(req, REQ_MAGIC);
VTAILQ_REMOVE(&oh->waitinglist, req, w_list);
DSL(DBG_WAITINGLIST, req->vsl->wid,
"kill from waiting list");
}
break;
}
if (!SES_Reschedule_Req(req))
continue;
/* Couldn't schedule, ditch */
wrk->stats->busy_wakeup--;
wrk->stats->busy_killed++;
AN (req->vcl);
VCL_Rel(&req->vcl);
sp = req->sp;
CHECK_OBJ_NOTNULL(sp, SESS_MAGIC);
CNT_AcctLogCharge(wrk->stats, req);
Req_Release(req);
SES_Delete(sp, SC_OVERLOAD, NAN);
DSL(DBG_WAITINGLIST, req->vsl->wid, "kill from waiting list");
(void)usleep(100000);
}
}
......@@ -657,11 +678,13 @@ void
HSH_Unbusy(struct worker *wrk, struct objcore *oc)
{
struct objhead *oh;
struct rush rush;
CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
oh = oc->objhead;
CHECK_OBJ(oh, OBJHEAD_MAGIC);
INIT_OBJ(&rush, RUSH_MAGIC);
AN(oc->stobj->stevedore);
AN(oc->flags & OC_F_BUSY);
......@@ -684,10 +707,11 @@ HSH_Unbusy(struct worker *wrk, struct objcore *oc)
VTAILQ_INSERT_HEAD(&oh->objcs, oc, hsh_list);
oc->flags &= ~OC_F_BUSY;
if (!VTAILQ_EMPTY(&oh->waitinglist))
hsh_rush(wrk, oh);
hsh_rush1(wrk, oh, &rush, 0);
Lck_Unlock(&oh->mtx);
if (!(oc->flags & OC_F_PRIVATE))
EXP_Insert(wrk, oc);
hsh_rush2(wrk, &rush);
}
/*====================================================================
......@@ -818,6 +842,7 @@ HSH_DerefObjCore(struct worker *wrk, struct objcore **ocp)
{
struct objcore *oc;
struct objhead *oh;
struct rush rush;
unsigned r;
AN(ocp);
......@@ -827,6 +852,7 @@ HSH_DerefObjCore(struct worker *wrk, struct objcore **ocp)
CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
assert(oc->refcnt > 0);
INIT_OBJ(&rush, RUSH_MAGIC);
oh = oc->objhead;
CHECK_OBJ_NOTNULL(oh, OBJHEAD_MAGIC);
......@@ -837,8 +863,9 @@ HSH_DerefObjCore(struct worker *wrk, struct objcore **ocp)
if (!r)
VTAILQ_REMOVE(&oh->objcs, oc, hsh_list);
if (!VTAILQ_EMPTY(&oh->waitinglist))
hsh_rush(wrk, oh);
hsh_rush1(wrk, oh, &rush, 0);
Lck_Unlock(&oh->mtx);
hsh_rush2(wrk, &rush);
if (r != 0)
return (r);
......@@ -861,10 +888,12 @@ int
HSH_DerefObjHead(struct worker *wrk, struct objhead **poh)
{
struct objhead *oh;
struct rush rush;
int r;
CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
TAKE_OBJ_NOTNULL(oh, poh, OBJHEAD_MAGIC);
INIT_OBJ(&rush, RUSH_MAGIC);
if (oh == private_oh) {
assert(VTAILQ_EMPTY(&oh->waitinglist));
......@@ -883,16 +912,14 @@ HSH_DerefObjHead(struct worker *wrk, struct objhead **poh)
* just make the hold the same ref's as objcore, that would
* confuse hashers.
*/
while (!VTAILQ_EMPTY(&oh->waitinglist)) {
Lck_Lock(&oh->mtx);
assert(oh->refcnt > 0);
r = oh->refcnt;
hsh_rush(wrk, oh);
Lck_Lock(&oh->mtx);
while (oh->refcnt == 1 && !VTAILQ_EMPTY(&oh->waitinglist)) {
hsh_rush1(wrk, oh, &rush, 1);
Lck_Unlock(&oh->mtx);
if (r > 1)
break;
usleep(100000);
hsh_rush2(wrk, &rush);
Lck_Lock(&oh->mtx);
}
Lck_Unlock(&oh->mtx);
assert(oh->refcnt > 0);
r = hash->deref(oh);
......
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