[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen master] tools/xenstore: switch write limiting to use millisecond time base
commit f28a3b49d3f338c4cd451905032b10bb2a7e9e8c Author: Juergen Gross <jgross@xxxxxxxx> AuthorDate: Tue May 30 10:54:08 2023 +0200 Commit: Julien Grall <jgrall@xxxxxxxxxx> CommitDate: Fri Jun 9 19:16:46 2023 +0100 tools/xenstore: switch write limiting to use millisecond time base There is no need to keep struct wrl_timestampt, as it serves the same purpose as the more simple time base provided by get_now(). Move some more stuff from xenstored_domain.h into xenstored_domain.c as it is being used nowhere else. Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Acked-by: Julien Grall <jgrall@xxxxxxxxxx> --- tools/xenstore/xenstored_core.c | 8 +++--- tools/xenstore/xenstored_core.h | 7 +++-- tools/xenstore/xenstored_domain.c | 56 +++++++++++++++++---------------------- tools/xenstore/xenstored_domain.h | 21 ++------------- 4 files changed, 32 insertions(+), 60 deletions(-) diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c index c467a704a1..e8f46495de 100644 --- a/tools/xenstore/xenstored_core.c +++ b/tools/xenstore/xenstored_core.c @@ -192,7 +192,7 @@ void reopen_log(void) } } -static uint64_t get_now_msec(void) +uint64_t get_now_msec(void) { struct timespec now_ts; @@ -510,7 +510,6 @@ fail: static void initialize_fds(int *p_sock_pollfd_idx, int *ptimeout) { struct connection *conn; - struct wrl_timestampt now; uint64_t msecs; if (fds) @@ -530,13 +529,12 @@ static void initialize_fds(int *p_sock_pollfd_idx, int *ptimeout) xce_pollfd_idx = set_fd(xenevtchn_fd(xce_handle), POLLIN|POLLPRI); - wrl_gettime_now(&now); - wrl_log_periodic(now); msecs = get_now_msec(); + wrl_log_periodic(msecs); list_for_each_entry(conn, &connections, list) { if (conn->domain) { - wrl_check_timeout(conn->domain, now, ptimeout); + wrl_check_timeout(conn->domain, msecs, ptimeout); check_event_timeout(conn, msecs, ptimeout); if (conn_can_read(conn) || (conn_can_write(conn) && diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h index 92d5b50f3c..84a611cbb5 100644 --- a/tools/xenstore/xenstored_core.h +++ b/tools/xenstore/xenstored_core.h @@ -47,10 +47,6 @@ /* DEFAULT_BUFFER_SIZE should be large enough for each errno string. */ #define DEFAULT_BUFFER_SIZE 16 -typedef int32_t wrl_creditt; -#define WRL_CREDIT_MAX (1000*1000*1000) -/* ^ satisfies non-overflow condition for wrl_xfer_credit */ - struct xs_state_connection; struct buffered_data @@ -320,6 +316,9 @@ extern bool keep_orphans; extern unsigned int timeout_watch_event_msec; +/* Get internal time in milliseconds. */ +uint64_t get_now_msec(void); + /* Map the kernel's xenstore page. */ void *xenbus_map(void); void unmap_xenbus(void *interface); diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c index 9ef0d994f6..632ddb5efc 100644 --- a/tools/xenstore/xenstored_domain.c +++ b/tools/xenstore/xenstored_domain.c @@ -99,6 +99,8 @@ struct quota soft_quotas[ACC_N] = { }, }; +typedef int32_t wrl_creditt; + struct domain { /* The id of this domain */ @@ -139,7 +141,7 @@ struct domain /* write rate limit */ wrl_creditt wrl_credit; /* [ -wrl_config_writecost, +_dburst ] */ - struct wrl_timestampt wrl_timestamp; + uint64_t wrl_timestamp; bool wrl_delay_logged; }; @@ -157,6 +159,17 @@ struct changed_domain static struct hashtable *domhash; +/* Write rate limiting */ + +/* Satisfies non-overflow condition for wrl_xfer_credit. */ +#define WRL_CREDIT_MAX (1000*1000*1000) +#define WRL_FACTOR 1000 /* for fixed-point arithmetic */ +#define WRL_RATE 200 +#define WRL_DBURST 10 +#define WRL_GBURST 1000 +#define WRL_NEWDOMS 5 +#define WRL_LOGEVERY 120 /* seconds */ + static wrl_creditt wrl_config_writecost = WRL_FACTOR; static wrl_creditt wrl_config_rate = WRL_RATE * WRL_FACTOR; static wrl_creditt wrl_config_dburst = WRL_DBURST * WRL_FACTOR; @@ -176,19 +189,6 @@ do { \ trace("wrl: " __VA_ARGS__); \ } while (0) -void wrl_gettime_now(struct wrl_timestampt *now_wt) -{ - struct timespec now_ts; - int r; - - r = clock_gettime(CLOCK_MONOTONIC, &now_ts); - if (r) - barf_perror("Could not find time (clock_gettime failed)"); - - now_wt->sec = now_ts.tv_sec; - now_wt->msec = now_ts.tv_nsec / 1000000; -} - static void wrl_xfer_credit(wrl_creditt *debit, wrl_creditt debit_floor, wrl_creditt *credit, wrl_creditt credit_ceil) /* @@ -215,7 +215,7 @@ static void wrl_xfer_credit(wrl_creditt *debit, wrl_creditt debit_floor, static void wrl_domain_new(struct domain *domain) { domain->wrl_credit = 0; - wrl_gettime_now(&domain->wrl_timestamp); + domain->wrl_timestamp = get_now_msec(); wrl_ndomains++; /* Steal up to DBURST from the reserve */ wrl_xfer_credit(&wrl_reserve, -wrl_config_newdoms_dburst, @@ -234,7 +234,7 @@ static void wrl_domain_destroy(struct domain *domain) &wrl_reserve, wrl_config_dburst); } -static void wrl_credit_update(struct domain *domain, struct wrl_timestampt now) +static void wrl_credit_update(struct domain *domain, uint64_t now) { /* * We want to calculate @@ -243,18 +243,12 @@ static void wrl_credit_update(struct domain *domain, struct wrl_timestampt now) * To avoid rounding errors from constantly adding small * amounts of credit, we only add credit for whole milliseconds. */ - long seconds = now.sec - domain->wrl_timestamp.sec; - long milliseconds = now.msec - domain->wrl_timestamp.msec; long msec; int64_t denom, num; wrl_creditt surplus; - seconds = MIN(seconds, 1000*1000); /* arbitrary, prevents overflow */ - msec = seconds * 1000 + milliseconds; - - if (msec < 0) - /* shouldn't happen with CLOCK_MONOTONIC */ - msec = 0; + /* Prevent overflow by limiting to 32 bits. */ + msec = MIN(now - domain->wrl_timestamp, 1000 * 1000 * 1000); /* 32x32 -> 64 cannot overflow */ denom = (int64_t)msec * wrl_config_rate; @@ -286,9 +280,7 @@ static void wrl_credit_update(struct domain *domain, struct wrl_timestampt now) (long)wrl_reserve, (long)surplus); } -void wrl_check_timeout(struct domain *domain, - struct wrl_timestampt now, - int *ptimeout) +void wrl_check_timeout(struct domain *domain, uint64_t now, int *ptimeout) { uint64_t num, denom; int wakeup; @@ -325,13 +317,13 @@ void wrl_check_timeout(struct domain *domain, void wrl_apply_debit_actual(struct domain *domain) { - struct wrl_timestampt now; + uint64_t now; if (!domain || !domain_is_unprivileged(domain->conn)) /* sockets and privileged domain escape the write rate limit */ return; - wrl_gettime_now(&now); + now = get_now_msec(); wrl_credit_update(domain, now); domain->wrl_credit -= wrl_config_writecost; @@ -346,14 +338,14 @@ void wrl_apply_debit_actual(struct domain *domain) } else if (!wrl_log_last_warning) { WRL_LOG(now, "rate limiting restarts\n"); } - wrl_log_last_warning = now.sec; + wrl_log_last_warning = now / 1000; } } -void wrl_log_periodic(struct wrl_timestampt now) +void wrl_log_periodic(uint64_t now) { if (wrl_log_last_warning && - (now.sec - wrl_log_last_warning) > WRL_LOGEVERY) { + (now / 1000 - wrl_log_last_warning) > WRL_LOGEVERY) { WRL_LOG(now, "not in force recently\n"); wrl_log_last_warning = 0; } diff --git a/tools/xenstore/xenstored_domain.h b/tools/xenstore/xenstored_domain.h index 89be643de4..bf63f3fcc6 100644 --- a/tools/xenstore/xenstored_domain.h +++ b/tools/xenstore/xenstored_domain.h @@ -146,27 +146,10 @@ void domain_reset_global_acc(void); bool domain_max_chk(const struct connection *conn, unsigned int what, unsigned int val); -/* Write rate limiting */ - -#define WRL_FACTOR 1000 /* for fixed-point arithmetic */ -#define WRL_RATE 200 -#define WRL_DBURST 10 -#define WRL_GBURST 1000 -#define WRL_NEWDOMS 5 -#define WRL_LOGEVERY 120 /* seconds */ - -struct wrl_timestampt { - time_t sec; - int msec; -}; - extern long wrl_ntransactions; -void wrl_gettime_now(struct wrl_timestampt *now_ts); -void wrl_check_timeout(struct domain *domain, - struct wrl_timestampt now, - int *ptimeout); -void wrl_log_periodic(struct wrl_timestampt now); +void wrl_check_timeout(struct domain *domain, uint64_t now, int *ptimeout); +void wrl_log_periodic(uint64_t now); void wrl_apply_debit_direct(struct connection *conn); void wrl_apply_debit_trans_commit(struct connection *conn); -- generated by git-patchbot for /home/xen/git/xen.git#master
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