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9978bd996b
freebsd/sys/kern/kern_racct.c
Andriy Gapon f87beb93e8 call racct_proc_ucred_changed() under the proc lock 
The lock is required to ensure that the switch to the new credentials
and the transfer of the process's accounting data from the old
credentials to the new ones is done atomically.  Otherwise, some updates
may be applied to the new credentials and then additionally transferred
from the old credentials if the updates happen after proc_set_cred() and
before racct_proc_ucred_changed().

The problem is especially pronounced for RACCT_RSS because
- there is a strict accounting for this resource (it's reclaimable)
- it's updated asynchronously by the vm daemon
- it's updated by setting an absolute value instead of applying a delta

I had to remove a call to rctl_proc_ucred_changed() from
racct_proc_ucred_changed() and make all callers of latter call the
former as well.  The reason is that rctl_proc_ucred_changed, as it is
implemented now, cannot be called while holding the proc lock, so the
lock is dropped after calling racct_proc_ucred_changed.  Additionally,
I've added calls to crhold / crfree around the rctl call, because
without the proc lock there is no gurantee that the new credentials,
owned by the process, will stay stable.  That does not eliminate a
possibility that the credentials passed to the rctl will get stale.
Ideally, rctl_proc_ucred_changed should be able to work under the proc
lock.

Many thanks to kib for pointing out the above problems.

PR:		222027
Discussed with:	kib
No comment:	trasz
MFC after:	2 weeks
Differential Revision: https://reviews.freebsd.org/D15048
2018-04-20 13:08:04 +00:00

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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2010 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Edward Tomasz Napierala under sponsorship
* from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_sched.h"
#include <sys/param.h>
#include <sys/buf.h>
#include <sys/systm.h>
#include <sys/eventhandler.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/lock.h>
#include <sys/loginclass.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/racct.h>
#include <sys/resourcevar.h>
#include <sys/sbuf.h>
#include <sys/sched.h>
#include <sys/sdt.h>
#include <sys/smp.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/sysproto.h>
#include <sys/umtx.h>
#include <machine/smp.h>
#ifdef RCTL
#include <sys/rctl.h>
#endif
#ifdef RACCT
FEATURE(racct, "Resource Accounting");
/*
* Do not block processes that have their %cpu usage <= pcpu_threshold.
*/
static int pcpu_threshold = 1;
#ifdef RACCT_DEFAULT_TO_DISABLED
int racct_enable = 0;
#else
int racct_enable = 1;
#endif
SYSCTL_NODE(_kern, OID_AUTO, racct, CTLFLAG_RW, 0, "Resource Accounting");
SYSCTL_UINT(_kern_racct, OID_AUTO, enable, CTLFLAG_RDTUN, &racct_enable,
0, "Enable RACCT/RCTL");
SYSCTL_UINT(_kern_racct, OID_AUTO, pcpu_threshold, CTLFLAG_RW, &pcpu_threshold,
0, "Processes with higher %cpu usage than this value can be throttled.");
/*
* How many seconds it takes to use the scheduler %cpu calculations. When a
* process starts, we compute its %cpu usage by dividing its runtime by the
* process wall clock time. After RACCT_PCPU_SECS pass, we use the value
* provided by the scheduler.
*/
#define RACCT_PCPU_SECS 3
struct mtx racct_lock;
MTX_SYSINIT(racct_lock, &racct_lock, "racct lock", MTX_DEF);
static uma_zone_t racct_zone;
static void racct_sub_racct(struct racct *dest, const struct racct *src);
static void racct_sub_cred_locked(struct ucred *cred, int resource,
uint64_t amount);
static void racct_add_cred_locked(struct ucred *cred, int resource,
uint64_t amount);
SDT_PROVIDER_DEFINE(racct);
SDT_PROBE_DEFINE3(racct, , rusage, add,
"struct proc *", "int", "uint64_t");
SDT_PROBE_DEFINE3(racct, , rusage, add__failure,
"struct proc *", "int", "uint64_t");
SDT_PROBE_DEFINE3(racct, , rusage, add__buf,
"struct proc *", "const struct buf *", "int");
SDT_PROBE_DEFINE3(racct, , rusage, add__cred,
"struct ucred *", "int", "uint64_t");
SDT_PROBE_DEFINE3(racct, , rusage, add__force,
"struct proc *", "int", "uint64_t");
SDT_PROBE_DEFINE3(racct, , rusage, set,
"struct proc *", "int", "uint64_t");
SDT_PROBE_DEFINE3(racct, , rusage, set__failure,
"struct proc *", "int", "uint64_t");
SDT_PROBE_DEFINE3(racct, , rusage, set__force,
"struct proc *", "int", "uint64_t");
SDT_PROBE_DEFINE3(racct, , rusage, sub,
"struct proc *", "int", "uint64_t");
SDT_PROBE_DEFINE3(racct, , rusage, sub__cred,
"struct ucred *", "int", "uint64_t");
SDT_PROBE_DEFINE1(racct, , racct, create,
"struct racct *");
SDT_PROBE_DEFINE1(racct, , racct, destroy,
"struct racct *");
SDT_PROBE_DEFINE2(racct, , racct, join,
"struct racct *", "struct racct *");
SDT_PROBE_DEFINE2(racct, , racct, join__failure,
"struct racct *", "struct racct *");
SDT_PROBE_DEFINE2(racct, , racct, leave,
"struct racct *", "struct racct *");
int racct_types[] = {
[RACCT_CPU] =
RACCT_IN_MILLIONS,
[RACCT_DATA] =
RACCT_RECLAIMABLE | RACCT_INHERITABLE | RACCT_DENIABLE,
[RACCT_STACK] =
RACCT_RECLAIMABLE | RACCT_INHERITABLE | RACCT_DENIABLE,
[RACCT_CORE] =
RACCT_DENIABLE,
[RACCT_RSS] =
RACCT_RECLAIMABLE,
[RACCT_MEMLOCK] =
RACCT_RECLAIMABLE | RACCT_DENIABLE,
[RACCT_NPROC] =
RACCT_RECLAIMABLE | RACCT_DENIABLE,
[RACCT_NOFILE] =
RACCT_RECLAIMABLE | RACCT_INHERITABLE | RACCT_DENIABLE,
[RACCT_VMEM] =
RACCT_RECLAIMABLE | RACCT_INHERITABLE | RACCT_DENIABLE,
[RACCT_NPTS] =
RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
[RACCT_SWAP] =
RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
[RACCT_NTHR] =
RACCT_RECLAIMABLE | RACCT_DENIABLE,
[RACCT_MSGQQUEUED] =
RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
[RACCT_MSGQSIZE] =
RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
[RACCT_NMSGQ] =
RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
[RACCT_NSEM] =
RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
[RACCT_NSEMOP] =
RACCT_RECLAIMABLE | RACCT_INHERITABLE | RACCT_DENIABLE,
[RACCT_NSHM] =
RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
[RACCT_SHMSIZE] =
RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
[RACCT_WALLCLOCK] =
RACCT_IN_MILLIONS,
[RACCT_PCTCPU] =
RACCT_DECAYING | RACCT_DENIABLE | RACCT_IN_MILLIONS,
[RACCT_READBPS] =
RACCT_DECAYING,
[RACCT_WRITEBPS] =
RACCT_DECAYING,
[RACCT_READIOPS] =
RACCT_DECAYING,
[RACCT_WRITEIOPS] =
RACCT_DECAYING };
static const fixpt_t RACCT_DECAY_FACTOR = 0.3 * FSCALE;
#ifdef SCHED_4BSD
/*
* Contains intermediate values for %cpu calculations to avoid using floating
* point in the kernel.
* ccpu_exp[k] = FSCALE * (ccpu/FSCALE)^k = FSCALE * exp(-k/20)
* It is needed only for the 4BSD scheduler, because in ULE, the ccpu equals to
* zero so the calculations are more straightforward.
*/
fixpt_t ccpu_exp[] = {
[0] = FSCALE * 1,
[1] = FSCALE * 0.95122942450071400909,
[2] = FSCALE * 0.90483741803595957316,
[3] = FSCALE * 0.86070797642505780722,
[4] = FSCALE * 0.81873075307798185866,
[5] = FSCALE * 0.77880078307140486824,
[6] = FSCALE * 0.74081822068171786606,
[7] = FSCALE * 0.70468808971871343435,
[8] = FSCALE * 0.67032004603563930074,
[9] = FSCALE * 0.63762815162177329314,
[10] = FSCALE * 0.60653065971263342360,
[11] = FSCALE * 0.57694981038048669531,
[12] = FSCALE * 0.54881163609402643262,
[13] = FSCALE * 0.52204577676101604789,
[14] = FSCALE * 0.49658530379140951470,
[15] = FSCALE * 0.47236655274101470713,
[16] = FSCALE * 0.44932896411722159143,
[17] = FSCALE * 0.42741493194872666992,
[18] = FSCALE * 0.40656965974059911188,
[19] = FSCALE * 0.38674102345450120691,
[20] = FSCALE * 0.36787944117144232159,
[21] = FSCALE * 0.34993774911115535467,
[22] = FSCALE * 0.33287108369807955328,
[23] = FSCALE * 0.31663676937905321821,
[24] = FSCALE * 0.30119421191220209664,
[25] = FSCALE * 0.28650479686019010032,
[26] = FSCALE * 0.27253179303401260312,
[27] = FSCALE * 0.25924026064589150757,
[28] = FSCALE * 0.24659696394160647693,
[29] = FSCALE * 0.23457028809379765313,
[30] = FSCALE * 0.22313016014842982893,
[31] = FSCALE * 0.21224797382674305771,
[32] = FSCALE * 0.20189651799465540848,
[33] = FSCALE * 0.19204990862075411423,
[34] = FSCALE * 0.18268352405273465022,
[35] = FSCALE * 0.17377394345044512668,
[36] = FSCALE * 0.16529888822158653829,
[37] = FSCALE * 0.15723716631362761621,
[38] = FSCALE * 0.14956861922263505264,
[39] = FSCALE * 0.14227407158651357185,
[40] = FSCALE * 0.13533528323661269189,
[41] = FSCALE * 0.12873490358780421886,
[42] = FSCALE * 0.12245642825298191021,
[43] = FSCALE * 0.11648415777349695786,
[44] = FSCALE * 0.11080315836233388333,
[45] = FSCALE * 0.10539922456186433678,
[46] = FSCALE * 0.10025884372280373372,
[47] = FSCALE * 0.09536916221554961888,
[48] = FSCALE * 0.09071795328941250337,
[49] = FSCALE * 0.08629358649937051097,
[50] = FSCALE * 0.08208499862389879516,
[51] = FSCALE * 0.07808166600115315231,
[52] = FSCALE * 0.07427357821433388042,
[53] = FSCALE * 0.07065121306042958674,
[54] = FSCALE * 0.06720551273974976512,
[55] = FSCALE * 0.06392786120670757270,
[56] = FSCALE * 0.06081006262521796499,
[57] = FSCALE * 0.05784432087483846296,
[58] = FSCALE * 0.05502322005640722902,
[59] = FSCALE * 0.05233970594843239308,
[60] = FSCALE * 0.04978706836786394297,
[61] = FSCALE * 0.04735892439114092119,
[62] = FSCALE * 0.04504920239355780606,
[63] = FSCALE * 0.04285212686704017991,
[64] = FSCALE * 0.04076220397836621516,
[65] = FSCALE * 0.03877420783172200988,
[66] = FSCALE * 0.03688316740124000544,
[67] = FSCALE * 0.03508435410084502588,
[68] = FSCALE * 0.03337326996032607948,
[69] = FSCALE * 0.03174563637806794323,
[70] = FSCALE * 0.03019738342231850073,
[71] = FSCALE * 0.02872463965423942912,
[72] = FSCALE * 0.02732372244729256080,
[73] = FSCALE * 0.02599112877875534358,
[74] = FSCALE * 0.02472352647033939120,
[75] = FSCALE * 0.02351774585600910823,
[76] = FSCALE * 0.02237077185616559577,
[77] = FSCALE * 0.02127973643837716938,
[78] = FSCALE * 0.02024191144580438847,
[79] = FSCALE * 0.01925470177538692429,
[80] = FSCALE * 0.01831563888873418029,
[81] = FSCALE * 0.01742237463949351138,
[82] = FSCALE * 0.01657267540176124754,
[83] = FSCALE * 0.01576441648485449082,
[84] = FSCALE * 0.01499557682047770621,
[85] = FSCALE * 0.01426423390899925527,
[86] = FSCALE * 0.01356855901220093175,
[87] = FSCALE * 0.01290681258047986886,
[88] = FSCALE * 0.01227733990306844117,
[89] = FSCALE * 0.01167856697039544521,
[90] = FSCALE * 0.01110899653824230649,
[91] = FSCALE * 0.01056720438385265337,
[92] = FSCALE * 0.01005183574463358164,
[93] = FSCALE * 0.00956160193054350793,
[94] = FSCALE * 0.00909527710169581709,
[95] = FSCALE * 0.00865169520312063417,
[96] = FSCALE * 0.00822974704902002884,
[97] = FSCALE * 0.00782837754922577143,
[98] = FSCALE * 0.00744658307092434051,
[99] = FSCALE * 0.00708340892905212004,
[100] = FSCALE * 0.00673794699908546709,
[101] = FSCALE * 0.00640933344625638184,
[102] = FSCALE * 0.00609674656551563610,
[103] = FSCALE * 0.00579940472684214321,
[104] = FSCALE * 0.00551656442076077241,
[105] = FSCALE * 0.00524751839918138427,
[106] = FSCALE * 0.00499159390691021621,
[107] = FSCALE * 0.00474815099941147558,
[108] = FSCALE * 0.00451658094261266798,
[109] = FSCALE * 0.00429630469075234057,
[110] = FSCALE * 0.00408677143846406699,
};
#endif
#define CCPU_EXP_MAX 110
/*
* This function is analogical to the getpcpu() function in the ps(1) command.
* They should both calculate in the same way so that the racct %cpu
* calculations are consistent with the values showed by the ps(1) tool.
* The calculations are more complex in the 4BSD scheduler because of the value
* of the ccpu variable. In ULE it is defined to be zero which saves us some
* work.
*/
static uint64_t
racct_getpcpu(struct proc *p, u_int pcpu)
{
u_int swtime;
#ifdef SCHED_4BSD
fixpt_t pctcpu, pctcpu_next;
#endif
#ifdef SMP
struct pcpu *pc;
int found;
#endif
fixpt_t p_pctcpu;
struct thread *td;
ASSERT_RACCT_ENABLED();
/*
* If the process is swapped out, we count its %cpu usage as zero.
* This behaviour is consistent with the userland ps(1) tool.
*/
if ((p->p_flag & P_INMEM) == 0)
return (0);
swtime = (ticks - p->p_swtick) / hz;
/*
* For short-lived processes, the sched_pctcpu() returns small
* values even for cpu intensive processes. Therefore we use
* our own estimate in this case.
*/
if (swtime < RACCT_PCPU_SECS)
return (pcpu);
p_pctcpu = 0;
FOREACH_THREAD_IN_PROC(p, td) {
if (td == PCPU_GET(idlethread))
continue;
#ifdef SMP
found = 0;
STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
if (td == pc->pc_idlethread) {
found = 1;
break;
}
}
if (found)
continue;
#endif
thread_lock(td);
#ifdef SCHED_4BSD
pctcpu = sched_pctcpu(td);
/* Count also the yet unfinished second. */
pctcpu_next = (pctcpu * ccpu_exp[1]) >> FSHIFT;
pctcpu_next += sched_pctcpu_delta(td);
p_pctcpu += max(pctcpu, pctcpu_next);
#else
/*
* In ULE the %cpu statistics are updated on every
* sched_pctcpu() call. So special calculations to
* account for the latest (unfinished) second are
* not needed.
*/
p_pctcpu += sched_pctcpu(td);
#endif
thread_unlock(td);
}
#ifdef SCHED_4BSD
if (swtime <= CCPU_EXP_MAX)
return ((100 * (uint64_t)p_pctcpu * 1000000) /
(FSCALE - ccpu_exp[swtime]));
#endif
return ((100 * (uint64_t)p_pctcpu * 1000000) / FSCALE);
}
static void
racct_add_racct(struct racct *dest, const struct racct *src)
{
int i;
ASSERT_RACCT_ENABLED();
RACCT_LOCK_ASSERT();
/*
* Update resource usage in dest.
*/
for (i = 0; i <= RACCT_MAX; i++) {
KASSERT(dest->r_resources[i] >= 0,
("%s: resource %d propagation meltdown: dest < 0",
__func__, i));
KASSERT(src->r_resources[i] >= 0,
("%s: resource %d propagation meltdown: src < 0",
__func__, i));
dest->r_resources[i] += src->r_resources[i];
}
}
static void
racct_sub_racct(struct racct *dest, const struct racct *src)
{
int i;
ASSERT_RACCT_ENABLED();
RACCT_LOCK_ASSERT();
/*
* Update resource usage in dest.
*/
for (i = 0; i <= RACCT_MAX; i++) {
if (!RACCT_IS_SLOPPY(i) && !RACCT_IS_DECAYING(i)) {
KASSERT(dest->r_resources[i] >= 0,
("%s: resource %d propagation meltdown: dest < 0",
__func__, i));
KASSERT(src->r_resources[i] >= 0,
("%s: resource %d propagation meltdown: src < 0",
__func__, i));
KASSERT(src->r_resources[i] <= dest->r_resources[i],
("%s: resource %d propagation meltdown: src > dest",
__func__, i));
}
if (RACCT_CAN_DROP(i)) {
dest->r_resources[i] -= src->r_resources[i];
if (dest->r_resources[i] < 0)
dest->r_resources[i] = 0;
}
}
}
void
racct_create(struct racct **racctp)
{
if (!racct_enable)
return;
SDT_PROBE1(racct, , racct, create, racctp);
KASSERT(*racctp == NULL, ("racct already allocated"));
*racctp = uma_zalloc(racct_zone, M_WAITOK | M_ZERO);
}
static void
racct_destroy_locked(struct racct **racctp)
{
struct racct *racct;
int i;
ASSERT_RACCT_ENABLED();
SDT_PROBE1(racct, , racct, destroy, racctp);
RACCT_LOCK_ASSERT();
KASSERT(racctp != NULL, ("NULL racctp"));
KASSERT(*racctp != NULL, ("NULL racct"));
racct = *racctp;
for (i = 0; i <= RACCT_MAX; i++) {
if (RACCT_IS_SLOPPY(i))
continue;
if (!RACCT_IS_RECLAIMABLE(i))
continue;
KASSERT(racct->r_resources[i] == 0,
("destroying non-empty racct: "
"%ju allocated for resource %d\n",
racct->r_resources[i], i));
}
uma_zfree(racct_zone, racct);
*racctp = NULL;
}
void
racct_destroy(struct racct **racct)
{
if (!racct_enable)
return;
RACCT_LOCK();
racct_destroy_locked(racct);
RACCT_UNLOCK();
}
/*
* Increase consumption of 'resource' by 'amount' for 'racct',
* but not its parents. Differently from other cases, 'amount' here
* may be less than zero.
*/
static void
racct_adjust_resource(struct racct *racct, int resource,
int64_t amount)
{
ASSERT_RACCT_ENABLED();
RACCT_LOCK_ASSERT();
KASSERT(racct != NULL, ("NULL racct"));
racct->r_resources[resource] += amount;
if (racct->r_resources[resource] < 0) {
KASSERT(RACCT_IS_SLOPPY(resource) || RACCT_IS_DECAYING(resource),
("%s: resource %d usage < 0", __func__, resource));
racct->r_resources[resource] = 0;
}
/*
* There are some cases where the racct %cpu resource would grow
* beyond 100% per core. For example in racct_proc_exit() we add
* the process %cpu usage to the ucred racct containers. If too
* many processes terminated in a short time span, the ucred %cpu
* resource could grow too much. Also, the 4BSD scheduler sometimes
* returns for a thread more than 100% cpu usage. So we set a sane
* boundary here to 100% * the maxumum number of CPUs.
*/
if ((resource == RACCT_PCTCPU) &&
(racct->r_resources[RACCT_PCTCPU] > 100 * 1000000 * (int64_t)MAXCPU))
racct->r_resources[RACCT_PCTCPU] = 100 * 1000000 * (int64_t)MAXCPU;
}
static int
racct_add_locked(struct proc *p, int resource, uint64_t amount, int force)
{
#ifdef RCTL
int error;
#endif
ASSERT_RACCT_ENABLED();
/*
* We need proc lock to dereference p->p_ucred.
*/
PROC_LOCK_ASSERT(p, MA_OWNED);
#ifdef RCTL
error = rctl_enforce(p, resource, amount);
if (error && !force && RACCT_IS_DENIABLE(resource)) {
SDT_PROBE3(racct, , rusage, add__failure, p, resource, amount);
return (error);
}
#endif
racct_adjust_resource(p->p_racct, resource, amount);
racct_add_cred_locked(p->p_ucred, resource, amount);
return (0);
}
/*
* Increase allocation of 'resource' by 'amount' for process 'p'.
* Return 0 if it's below limits, or errno, if it's not.
*/
int
racct_add(struct proc *p, int resource, uint64_t amount)
{
int error;
if (!racct_enable)
return (0);
SDT_PROBE3(racct, , rusage, add, p, resource, amount);
RACCT_LOCK();
error = racct_add_locked(p, resource, amount, 0);
RACCT_UNLOCK();
return (error);
}
/*
* Increase allocation of 'resource' by 'amount' for process 'p'.
* Doesn't check for limits and never fails.
*/
void
racct_add_force(struct proc *p, int resource, uint64_t amount)
{
if (!racct_enable)
return;
SDT_PROBE3(racct, , rusage, add__force, p, resource, amount);
RACCT_LOCK();
racct_add_locked(p, resource, amount, 1);
RACCT_UNLOCK();
}
static void
racct_add_cred_locked(struct ucred *cred, int resource, uint64_t amount)
{
struct prison *pr;
ASSERT_RACCT_ENABLED();
racct_adjust_resource(cred->cr_ruidinfo->ui_racct, resource, amount);
for (pr = cred->cr_prison; pr != NULL; pr = pr->pr_parent)
racct_adjust_resource(pr->pr_prison_racct->prr_racct, resource,
amount);
racct_adjust_resource(cred->cr_loginclass->lc_racct, resource, amount);
}
/*
* Increase allocation of 'resource' by 'amount' for credential 'cred'.
* Doesn't check for limits and never fails.
*/
void
racct_add_cred(struct ucred *cred, int resource, uint64_t amount)
{
if (!racct_enable)
return;
SDT_PROBE3(racct, , rusage, add__cred, cred, resource, amount);
RACCT_LOCK();
racct_add_cred_locked(cred, resource, amount);
RACCT_UNLOCK();
}
/*
* Account for disk IO resource consumption. Checks for limits,
* but never fails, due to disk limits being undeniable.
*/
void
racct_add_buf(struct proc *p, const struct buf *bp, int is_write)
{
ASSERT_RACCT_ENABLED();
PROC_LOCK_ASSERT(p, MA_OWNED);
SDT_PROBE3(racct, , rusage, add__buf, p, bp, is_write);
RACCT_LOCK();
if (is_write) {
racct_add_locked(curproc, RACCT_WRITEBPS, bp->b_bcount, 1);
racct_add_locked(curproc, RACCT_WRITEIOPS, 1, 1);
} else {
racct_add_locked(curproc, RACCT_READBPS, bp->b_bcount, 1);
racct_add_locked(curproc, RACCT_READIOPS, 1, 1);
}
RACCT_UNLOCK();
}
static int
racct_set_locked(struct proc *p, int resource, uint64_t amount, int force)
{
int64_t old_amount, decayed_amount, diff_proc, diff_cred;
#ifdef RCTL
int error;
#endif
ASSERT_RACCT_ENABLED();
/*
* We need proc lock to dereference p->p_ucred.
*/
PROC_LOCK_ASSERT(p, MA_OWNED);
old_amount = p->p_racct->r_resources[resource];
/*
* The diffs may be negative.
*/
diff_proc = amount - old_amount;
if (resource == RACCT_PCTCPU) {
/*
* Resources in per-credential racct containers may decay.
* If this is the case, we need to calculate the difference
* between the new amount and the proportional value of the
* old amount that has decayed in the ucred racct containers.
*/
decayed_amount = old_amount * RACCT_DECAY_FACTOR / FSCALE;
diff_cred = amount - decayed_amount;
} else
diff_cred = diff_proc;
#ifdef notyet
KASSERT(diff_proc >= 0 || RACCT_CAN_DROP(resource),
("%s: usage of non-droppable resource %d dropping", __func__,
resource));
#endif
#ifdef RCTL
if (diff_proc > 0) {
error = rctl_enforce(p, resource, diff_proc);
if (error && !force && RACCT_IS_DENIABLE(resource)) {
SDT_PROBE3(racct, , rusage, set__failure, p, resource,
amount);
return (error);
}
}
#endif
racct_adjust_resource(p->p_racct, resource, diff_proc);
if (diff_cred > 0)
racct_add_cred_locked(p->p_ucred, resource, diff_cred);
else if (diff_cred < 0)
racct_sub_cred_locked(p->p_ucred, resource, -diff_cred);
return (0);
}
/*
* Set allocation of 'resource' to 'amount' for process 'p'.
* Return 0 if it's below limits, or errno, if it's not.
*
* Note that decreasing the allocation always returns 0,
* even if it's above the limit.
*/
int
racct_set(struct proc *p, int resource, uint64_t amount)
{
int error;
if (!racct_enable)
return (0);
SDT_PROBE3(racct, , rusage, set__force, p, resource, amount);
RACCT_LOCK();
error = racct_set_locked(p, resource, amount, 0);
RACCT_UNLOCK();
return (error);
}
void
racct_set_force(struct proc *p, int resource, uint64_t amount)
{
if (!racct_enable)
return;
SDT_PROBE3(racct, , rusage, set, p, resource, amount);
RACCT_LOCK();
racct_set_locked(p, resource, amount, 1);
RACCT_UNLOCK();
}
/*
* Returns amount of 'resource' the process 'p' can keep allocated.
* Allocating more than that would be denied, unless the resource
* is marked undeniable. Amount of already allocated resource does
* not matter.
*/
uint64_t
racct_get_limit(struct proc *p, int resource)
{
#ifdef RCTL
uint64_t available;
if (!racct_enable)
return (UINT64_MAX);
RACCT_LOCK();
available = rctl_get_limit(p, resource);
RACCT_UNLOCK();
return (available);
#else
return (UINT64_MAX);
#endif
}
/*
* Returns amount of 'resource' the process 'p' can keep allocated.
* Allocating more than that would be denied, unless the resource
* is marked undeniable. Amount of already allocated resource does
* matter.
*/
uint64_t
racct_get_available(struct proc *p, int resource)
{
#ifdef RCTL
uint64_t available;
if (!racct_enable)
return (UINT64_MAX);
RACCT_LOCK();
available = rctl_get_available(p, resource);
RACCT_UNLOCK();
return (available);
#else
return (UINT64_MAX);
#endif
}
/*
* Returns amount of the %cpu resource that process 'p' can add to its %cpu
* utilization. Adding more than that would lead to the process being
* throttled.
*/
static int64_t
racct_pcpu_available(struct proc *p)
{
#ifdef RCTL
uint64_t available;
ASSERT_RACCT_ENABLED();
RACCT_LOCK();
available = rctl_pcpu_available(p);
RACCT_UNLOCK();
return (available);
#else
return (INT64_MAX);
#endif
}
/*
* Decrease allocation of 'resource' by 'amount' for process 'p'.
*/
void
racct_sub(struct proc *p, int resource, uint64_t amount)
{
if (!racct_enable)
return;
SDT_PROBE3(racct, , rusage, sub, p, resource, amount);
/*
* We need proc lock to dereference p->p_ucred.
*/
PROC_LOCK_ASSERT(p, MA_OWNED);
KASSERT(RACCT_CAN_DROP(resource),
("%s: called for non-droppable resource %d", __func__, resource));
RACCT_LOCK();
KASSERT(amount <= p->p_racct->r_resources[resource],
("%s: freeing %ju of resource %d, which is more "
"than allocated %jd for %s (pid %d)", __func__, amount, resource,
(intmax_t)p->p_racct->r_resources[resource], p->p_comm, p->p_pid));
racct_adjust_resource(p->p_racct, resource, -amount);
racct_sub_cred_locked(p->p_ucred, resource, amount);
RACCT_UNLOCK();
}
static void
racct_sub_cred_locked(struct ucred *cred, int resource, uint64_t amount)
{
struct prison *pr;
ASSERT_RACCT_ENABLED();
racct_adjust_resource(cred->cr_ruidinfo->ui_racct, resource, -amount);
for (pr = cred->cr_prison; pr != NULL; pr = pr->pr_parent)
racct_adjust_resource(pr->pr_prison_racct->prr_racct, resource,
-amount);
racct_adjust_resource(cred->cr_loginclass->lc_racct, resource, -amount);
}
/*
* Decrease allocation of 'resource' by 'amount' for credential 'cred'.
*/
void
racct_sub_cred(struct ucred *cred, int resource, uint64_t amount)
{
if (!racct_enable)
return;
SDT_PROBE3(racct, , rusage, sub__cred, cred, resource, amount);
#ifdef notyet
KASSERT(RACCT_CAN_DROP(resource),
("%s: called for resource %d which can not drop", __func__,
resource));
#endif
RACCT_LOCK();
racct_sub_cred_locked(cred, resource, amount);
RACCT_UNLOCK();
}
/*
* Inherit resource usage information from the parent process.
*/
int
racct_proc_fork(struct proc *parent, struct proc *child)
{
int i, error = 0;
if (!racct_enable)
return (0);
/*
* Create racct for the child process.
*/
racct_create(&child->p_racct);
PROC_LOCK(parent);
PROC_LOCK(child);
RACCT_LOCK();
#ifdef RCTL
error = rctl_proc_fork(parent, child);
if (error != 0)
goto out;
#endif
/* Init process cpu time. */
child->p_prev_runtime = 0;
child->p_throttled = 0;
/*
* Inherit resource usage.
*/
for (i = 0; i <= RACCT_MAX; i++) {
if (parent->p_racct->r_resources[i] == 0 ||
!RACCT_IS_INHERITABLE(i))
continue;
error = racct_set_locked(child, i,
parent->p_racct->r_resources[i], 0);
if (error != 0)
goto out;
}
error = racct_add_locked(child, RACCT_NPROC, 1, 0);
error += racct_add_locked(child, RACCT_NTHR, 1, 0);
out:
RACCT_UNLOCK();
PROC_UNLOCK(child);
PROC_UNLOCK(parent);
if (error != 0)
racct_proc_exit(child);
return (error);
}
/*
* Called at the end of fork1(), to handle rules that require the process
* to be fully initialized.
*/
void
racct_proc_fork_done(struct proc *child)
{
if (!racct_enable)
return;
PROC_LOCK_ASSERT(child, MA_OWNED);
#ifdef RCTL
RACCT_LOCK();
rctl_enforce(child, RACCT_NPROC, 0);
rctl_enforce(child, RACCT_NTHR, 0);
RACCT_UNLOCK();
#endif
}
void
racct_proc_exit(struct proc *p)
{
struct timeval wallclock;
uint64_t pct_estimate, pct, runtime;
int i;
if (!racct_enable)
return;
PROC_LOCK(p);
/*
* We don't need to calculate rux, proc_reap() has already done this.
*/
runtime = cputick2usec(p->p_rux.rux_runtime);
#ifdef notyet
KASSERT(runtime >= p->p_prev_runtime, ("runtime < p_prev_runtime"));
#else
if (runtime < p->p_prev_runtime)
runtime = p->p_prev_runtime;
#endif
microuptime(&wallclock);
timevalsub(&wallclock, &p->p_stats->p_start);
if (wallclock.tv_sec > 0 || wallclock.tv_usec > 0) {
pct_estimate = (1000000 * runtime * 100) /
((uint64_t)wallclock.tv_sec * 1000000 +
wallclock.tv_usec);
} else
pct_estimate = 0;
pct = racct_getpcpu(p, pct_estimate);
RACCT_LOCK();
racct_set_locked(p, RACCT_CPU, runtime, 0);
racct_add_cred_locked(p->p_ucred, RACCT_PCTCPU, pct);
KASSERT(p->p_racct->r_resources[RACCT_RSS] == 0,
("process reaped with %ju allocated for RSS\n",
p->p_racct->r_resources[RACCT_RSS]));
for (i = 0; i <= RACCT_MAX; i++) {
if (p->p_racct->r_resources[i] == 0)
continue;
if (!RACCT_IS_RECLAIMABLE(i))
continue;
racct_set_locked(p, i, 0, 0);
}
#ifdef RCTL
rctl_racct_release(p->p_racct);
#endif
racct_destroy_locked(&p->p_racct);
RACCT_UNLOCK();
PROC_UNLOCK(p);
}
/*
* Called after credentials change, to move resource utilisation
* between raccts.
*/
void
racct_proc_ucred_changed(struct proc *p, struct ucred *oldcred,
struct ucred *newcred)
{
struct uidinfo *olduip, *newuip;
struct loginclass *oldlc, *newlc;
struct prison *oldpr, *newpr, *pr;
if (!racct_enable)
return;
PROC_LOCK_ASSERT(p, MA_OWNED);
newuip = newcred->cr_ruidinfo;
olduip = oldcred->cr_ruidinfo;
newlc = newcred->cr_loginclass;
oldlc = oldcred->cr_loginclass;
newpr = newcred->cr_prison;
oldpr = oldcred->cr_prison;
RACCT_LOCK();
if (newuip != olduip) {
racct_sub_racct(olduip->ui_racct, p->p_racct);
racct_add_racct(newuip->ui_racct, p->p_racct);
}
if (newlc != oldlc) {
racct_sub_racct(oldlc->lc_racct, p->p_racct);
racct_add_racct(newlc->lc_racct, p->p_racct);
}
if (newpr != oldpr) {
for (pr = oldpr; pr != NULL; pr = pr->pr_parent)
racct_sub_racct(pr->pr_prison_racct->prr_racct,
p->p_racct);
for (pr = newpr; pr != NULL; pr = pr->pr_parent)
racct_add_racct(pr->pr_prison_racct->prr_racct,
p->p_racct);
}
RACCT_UNLOCK();
}
void
racct_move(struct racct *dest, struct racct *src)
{
ASSERT_RACCT_ENABLED();
RACCT_LOCK();
racct_add_racct(dest, src);
racct_sub_racct(src, src);
RACCT_UNLOCK();
}
/*
* Make the process sleep in userret() for 'timeout' ticks. Setting
* timeout to -1 makes it sleep until woken up by racct_proc_wakeup().
*/
void
racct_proc_throttle(struct proc *p, int timeout)
{
struct thread *td;
#ifdef SMP
int cpuid;
#endif
KASSERT(timeout != 0, ("timeout %d", timeout));
ASSERT_RACCT_ENABLED();
PROC_LOCK_ASSERT(p, MA_OWNED);
/*
* Do not block kernel processes. Also do not block processes with
* low %cpu utilization to improve interactivity.
*/
if ((p->p_flag & (P_SYSTEM | P_KPROC)) != 0)
return;
if (p->p_throttled < 0 || (timeout > 0 && p->p_throttled > timeout))
return;
p->p_throttled = timeout;
FOREACH_THREAD_IN_PROC(p, td) {
thread_lock(td);
switch (td->td_state) {
case TDS_RUNQ:
/*
* If the thread is on the scheduler run-queue, we can
* not just remove it from there. So we set the flag
* TDF_NEEDRESCHED for the thread, so that once it is
* running, it is taken off the cpu as soon as possible.
*/
td->td_flags |= TDF_NEEDRESCHED;
break;
case TDS_RUNNING:
/*
* If the thread is running, we request a context
* switch for it by setting the TDF_NEEDRESCHED flag.
*/
td->td_flags |= TDF_NEEDRESCHED;
#ifdef SMP
cpuid = td->td_oncpu;
if ((cpuid != NOCPU) && (td != curthread))
ipi_cpu(cpuid, IPI_AST);
#endif
break;
default:
break;
}
thread_unlock(td);
}
}
static void
racct_proc_wakeup(struct proc *p)
{
ASSERT_RACCT_ENABLED();
PROC_LOCK_ASSERT(p, MA_OWNED);
if (p->p_throttled != 0) {
p->p_throttled = 0;
wakeup(p->p_racct);
}
}
static void
racct_decay_callback(struct racct *racct, void *dummy1, void *dummy2)
{
int64_t r_old, r_new;
ASSERT_RACCT_ENABLED();
RACCT_LOCK_ASSERT();
#ifdef RCTL
rctl_throttle_decay(racct, RACCT_READBPS);
rctl_throttle_decay(racct, RACCT_WRITEBPS);
rctl_throttle_decay(racct, RACCT_READIOPS);
rctl_throttle_decay(racct, RACCT_WRITEIOPS);
#endif
r_old = racct->r_resources[RACCT_PCTCPU];
/* If there is nothing to decay, just exit. */
if (r_old <= 0)
return;
r_new = r_old * RACCT_DECAY_FACTOR / FSCALE;
racct->r_resources[RACCT_PCTCPU] = r_new;
}
static void
racct_decay_pre(void)
{
RACCT_LOCK();
}
static void
racct_decay_post(void)
{
RACCT_UNLOCK();
}
static void
racct_decay(void)
{
ASSERT_RACCT_ENABLED();
ui_racct_foreach(racct_decay_callback, racct_decay_pre,
racct_decay_post, NULL, NULL);
loginclass_racct_foreach(racct_decay_callback, racct_decay_pre,
racct_decay_post, NULL, NULL);
prison_racct_foreach(racct_decay_callback, racct_decay_pre,
racct_decay_post, NULL, NULL);
}
static void
racctd(void)
{
struct thread *td;
struct proc *p;
struct timeval wallclock;
uint64_t pct, pct_estimate, runtime;
ASSERT_RACCT_ENABLED();
for (;;) {
racct_decay();
sx_slock(&allproc_lock);
LIST_FOREACH(p, &zombproc, p_list) {
PROC_LOCK(p);
racct_set(p, RACCT_PCTCPU, 0);
PROC_UNLOCK(p);
}
FOREACH_PROC_IN_SYSTEM(p) {
PROC_LOCK(p);
if (p->p_state != PRS_NORMAL) {
PROC_UNLOCK(p);
continue;
}
microuptime(&wallclock);
timevalsub(&wallclock, &p->p_stats->p_start);
PROC_STATLOCK(p);
FOREACH_THREAD_IN_PROC(p, td)
ruxagg(p, td);
runtime = cputick2usec(p->p_rux.rux_runtime);
PROC_STATUNLOCK(p);
#ifdef notyet
KASSERT(runtime >= p->p_prev_runtime,
("runtime < p_prev_runtime"));
#else
if (runtime < p->p_prev_runtime)
runtime = p->p_prev_runtime;
#endif
p->p_prev_runtime = runtime;
if (wallclock.tv_sec > 0 || wallclock.tv_usec > 0) {
pct_estimate = (1000000 * runtime * 100) /
((uint64_t)wallclock.tv_sec * 1000000 +
wallclock.tv_usec);
} else
pct_estimate = 0;
pct = racct_getpcpu(p, pct_estimate);
RACCT_LOCK();
#ifdef RCTL
rctl_throttle_decay(p->p_racct, RACCT_READBPS);
rctl_throttle_decay(p->p_racct, RACCT_WRITEBPS);
rctl_throttle_decay(p->p_racct, RACCT_READIOPS);
rctl_throttle_decay(p->p_racct, RACCT_WRITEIOPS);
#endif
racct_set_locked(p, RACCT_PCTCPU, pct, 1);
racct_set_locked(p, RACCT_CPU, runtime, 0);
racct_set_locked(p, RACCT_WALLCLOCK,
(uint64_t)wallclock.tv_sec * 1000000 +
wallclock.tv_usec, 0);
RACCT_UNLOCK();
PROC_UNLOCK(p);
}
/*
* To ensure that processes are throttled in a fair way, we need
* to iterate over all processes again and check the limits
* for %cpu resource only after ucred racct containers have been
* properly filled.
*/
FOREACH_PROC_IN_SYSTEM(p) {
PROC_LOCK(p);
if (p->p_state != PRS_NORMAL) {
PROC_UNLOCK(p);
continue;
}
if (racct_pcpu_available(p) <= 0) {
if (p->p_racct->r_resources[RACCT_PCTCPU] >
pcpu_threshold)
racct_proc_throttle(p, -1);
} else if (p->p_throttled == -1) {
racct_proc_wakeup(p);
}
PROC_UNLOCK(p);
}
sx_sunlock(&allproc_lock);
pause("-", hz);
}
}
static struct kproc_desc racctd_kp = {
"racctd",
racctd,
NULL
};
static void
racctd_init(void)
{
if (!racct_enable)
return;
kproc_start(&racctd_kp);
}
SYSINIT(racctd, SI_SUB_RACCTD, SI_ORDER_FIRST, racctd_init, NULL);
static void
racct_init(void)
{
if (!racct_enable)
return;
racct_zone = uma_zcreate("racct", sizeof(struct racct),
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
/*
* XXX: Move this somewhere.
*/
prison0.pr_prison_racct = prison_racct_find("0");
}
SYSINIT(racct, SI_SUB_RACCT, SI_ORDER_FIRST, racct_init, NULL);
#endif /* !RACCT */
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