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The dualism between epoch_tracker and epoch_thread is fragile and

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unnecessary. So, expose CK types to kernel and use a single normal
structure for epoch_tracker.

Reviewed by:	jtl, gallatin
This commit is contained in:
Gleb Smirnoff 2018-11-13 23:20:55 +00:00
parent f1bac7bb74
commit 9f360eecf9
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=340415
2 changed files with 35 additions and 50 deletions
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53
sys/kern/subr_epoch.c
View File

@ -55,25 +55,13 @@ __FBSDID("$FreeBSD$");
static MALLOC_DEFINE(M_EPOCH, "epoch", "epoch based reclamation");
typedef struct epoch_thread {
#ifdef EPOCH_TRACKER_DEBUG
uint64_t et_magic_pre;
#endif
TAILQ_ENTRY(epoch_thread) et_link; /* Epoch queue. */
struct thread *et_td; /* pointer to thread in section */
ck_epoch_section_t et_section; /* epoch section object */
#ifdef EPOCH_TRACKER_DEBUG
uint64_t et_magic_post;
#endif
} *epoch_thread_t;
TAILQ_HEAD (epoch_tdlist, epoch_thread);
#ifdef __amd64__
#define EPOCH_ALIGN CACHE_LINE_SIZE*2
#else
#define EPOCH_ALIGN CACHE_LINE_SIZE
#endif
TAILQ_HEAD (epoch_tdlist, epoch_tracker);
typedef struct epoch_record {
ck_epoch_record_t er_read_record;
ck_epoch_record_t er_write_record;
@ -252,27 +240,25 @@ void
epoch_enter_preempt(epoch_t epoch, epoch_tracker_t et)
{
struct epoch_record *er;
struct epoch_thread *etd;
struct thread_lite *td;
MPASS(cold || epoch != NULL);
INIT_CHECK(epoch);
etd = (void *)et;
MPASS(epoch->e_flags & EPOCH_PREEMPT);
#ifdef EPOCH_TRACKER_DEBUG
etd->et_magic_pre = EPOCH_MAGIC0;
etd->et_magic_post = EPOCH_MAGIC1;
et->et_magic_pre = EPOCH_MAGIC0;
et->et_magic_post = EPOCH_MAGIC1;
#endif
td = (struct thread_lite *)curthread;
etd->et_td = (void*)td;
et->et_td = (void*)td;
td->td_epochnest++;
critical_enter();
sched_pin_lite(td);
td->td_pre_epoch_prio = td->td_priority;
er = epoch_currecord(epoch);
TAILQ_INSERT_TAIL(&er->er_tdlist, etd, et_link);
ck_epoch_begin(&er->er_read_record, (ck_epoch_section_t *)&etd->et_section);
TAILQ_INSERT_TAIL(&er->er_tdlist, et, et_link);
ck_epoch_begin(&er->er_read_record, &et->et_section);
critical_exit();
}
@ -296,7 +282,6 @@ void
epoch_exit_preempt(epoch_t epoch, epoch_tracker_t et)
{
struct epoch_record *er;
struct epoch_thread *etd;
struct thread_lite *td;
INIT_CHECK(epoch);
@ -307,19 +292,19 @@ epoch_exit_preempt(epoch_t epoch, epoch_tracker_t et)
td->td_epochnest--;
er = epoch_currecord(epoch);
MPASS(epoch->e_flags & EPOCH_PREEMPT);
etd = (void *)et;
MPASS(etd != NULL);
MPASS(etd->et_td == (struct thread *)td);
MPASS(et != NULL);
MPASS(et->et_td == (struct thread *)td);
#ifdef EPOCH_TRACKER_DEBUG
MPASS(etd->et_magic_pre == EPOCH_MAGIC0);
MPASS(etd->et_magic_post == EPOCH_MAGIC1);
etd->et_magic_pre = 0;
etd->et_magic_post = 0;
MPASS(et->et_magic_pre == EPOCH_MAGIC0);
MPASS(et->et_magic_post == EPOCH_MAGIC1);
et->et_magic_pre = 0;
et->et_magic_post = 0;
#endif
etd->et_td = (void*)0xDEADBEEF;
ck_epoch_end(&er->er_read_record,
(ck_epoch_section_t *)&etd->et_section);
TAILQ_REMOVE(&er->er_tdlist, etd, et_link);
#ifdef INVARIANTS
et->et_td = (void*)0xDEADBEEF;
#endif
ck_epoch_end(&er->er_read_record, &et->et_section);
TAILQ_REMOVE(&er->er_tdlist, et, et_link);
er->er_gen++;
if (__predict_false(td->td_pre_epoch_prio != td->td_priority))
epoch_adjust_prio((struct thread *)td, td->td_pre_epoch_prio);
@ -351,7 +336,7 @@ epoch_block_handler_preempt(struct ck_epoch *global __unused, ck_epoch_record_t
{
epoch_record_t record;
struct thread *td, *owner, *curwaittd;
struct epoch_thread *tdwait;
struct epoch_tracker *tdwait;
struct turnstile *ts;
struct lock_object *lock;
int spincount, gen;
@ -633,7 +618,7 @@ epoch_call_task(void *arg __unused)
int
in_epoch_verbose(epoch_t epoch, int dump_onfail)
{
struct epoch_thread *tdwait;
struct epoch_tracker *tdwait;
struct thread *td;
epoch_record_t er;

32
sys/sys/epoch.h
View File

@ -30,31 +30,16 @@
#ifndef _SYS_EPOCH_H_
#define _SYS_EPOCH_H_
/*
* XXXGL: temporarily keep epoch_tracker exposed to userland until
* we remove trackers embedded into network structs.
*/
struct epoch_context {
void *data[2];
} __aligned(sizeof(void *));
typedef struct epoch_context *epoch_context_t;
struct epoch_tracker {
void *datap[3];
#ifdef EPOCH_TRACKER_DEBUG
int datai[5];
#else
int datai[1];
#endif
} __aligned(sizeof(void *));
typedef struct epoch_tracker *epoch_tracker_t;
#ifdef _KERNEL
#include <sys/lock.h>
#include <sys/pcpu.h>
#include <ck_epoch.h>
struct epoch;
typedef struct epoch *epoch_t;
@ -65,6 +50,21 @@ typedef struct epoch *epoch_t;
extern epoch_t global_epoch;
extern epoch_t global_epoch_preempt;
struct epoch_tracker {
#ifdef EPOCH_TRACKER_DEBUG
#define EPOCH_MAGIC0 0xFADECAFEF00DD00D
#define EPOCH_MAGIC1 0xBADDBABEDEEDFEED
uint64_t et_magic_pre;
#endif
TAILQ_ENTRY(epoch_tracker) et_link;
struct thread *et_td;
ck_epoch_section_t et_section;
#ifdef EPOCH_TRACKER_DEBUG
uint64_t et_magic_post;
#endif
} __aligned(sizeof(void *));
typedef struct epoch_tracker *epoch_tracker_t;
epoch_t epoch_alloc(int flags);
void epoch_free(epoch_t epoch);
void epoch_wait(epoch_t epoch);