Page MenuHomeFreeBSD
Files F137990640

D13693.id37245.diff
No OneTemporary
Actions

D13693.id37245.diff
View Options

Index: sys/vm/vm_swapout.c
===================================================================
--- sys/vm/vm_swapout.c
+++ sys/vm/vm_swapout.c
@@ -730,133 +730,80 @@
struct proc *p;
struct thread *td;
int minslptime, slptime;
- bool didswap;
+ bool didswap, doswap;
minslptime = 100000;
didswap = false;
-retry:
sx_slock(&allproc_lock);
FOREACH_PROC_IN_SYSTEM(p) {
- PROC_LOCK(p);
/*
- * Watch out for a process in
- * creation. It may have no
- * address space or lock yet.
+ * Filter out not yet fully constructed processes. Do
+ * not swap out held processes. Avoid processes which
+ * are system, exiting, traced, already swapped out or
+ * are in the process of being swapped in or out.
*/
- if (p->p_state == PRS_NEW) {
- PROC_UNLOCK(p);
- continue;
- }
- /*
- * An aio daemon switches its
- * address space while running.
- * Perform a quick check whether
- * a process has P_SYSTEM.
- * Filter out exiting processes.
- */
- if ((p->p_flag & (P_SYSTEM | P_WEXIT)) != 0) {
+ PROC_LOCK(p);
+ if (p->p_state != PRS_NORMAL || p->p_lock != 0 || (p->p_flag &
+ (P_SYSTEM | P_WEXIT | P_STOPPED_SINGLE | P_TRACED |
+ P_SWAPPINGOUT | P_SWAPPINGIN | P_INMEM)) != P_INMEM) {
PROC_UNLOCK(p);
continue;
}
+
_PHOLD_LITE(p);
- PROC_UNLOCK(p);
sx_sunlock(&allproc_lock);
- PROC_LOCK(p);
- if (p->p_lock != 1 || (p->p_flag & (P_STOPPED_SINGLE |
- P_TRACED | P_SYSTEM)) != 0)
- goto nextproc;
-
- /*
- * Only aiod changes vmspace. However, it will be
- * skipped because of the if statement above checking
- * for P_SYSTEM.
- */
- if ((p->p_flag & (P_INMEM | P_SWAPPINGOUT | P_SWAPPINGIN)) !=
- P_INMEM)
- goto nextproc;
+ doswap = true;
+ FOREACH_THREAD_IN_PROC(p, td) {
+ thread_lock(td);
+ slptime = (ticks - td->td_slptick) / hz;
- switch (p->p_state) {
- default:
/*
- * Don't swap out processes in any sort
- * of 'special' state.
+ * Do not swapout a realtime process.
+ * Guarantee swap_idle_threshold1 time in memory.
+ * If the system is under memory stress, or if
+ * we are swapping idle processes >=
+ * swap_idle_threshold2, then swap the process
+ * out.
*/
- break;
+ if (PRI_IS_REALTIME(td->td_pri_class) ||
+ slptime < swap_idle_threshold1 ||
+ !thread_safetoswapout(td) ||
+ ((action & VM_SWAP_NORMAL) == 0 &&
+ ((action & VM_SWAP_IDLE) == 0 ||
+ slptime < swap_idle_threshold2)))
+ doswap = false;
- case PRS_NORMAL:
- /*
- * do not swapout a realtime process
- * Check all the thread groups..
- */
- FOREACH_THREAD_IN_PROC(p, td) {
- thread_lock(td);
- if (PRI_IS_REALTIME(td->td_pri_class)) {
- thread_unlock(td);
- goto nextproc;
- }
- slptime = (ticks - td->td_slptick) / hz;
- /*
- * Guarantee swap_idle_threshold1
- * time in memory.
- */
- if (slptime < swap_idle_threshold1) {
- thread_unlock(td);
- goto nextproc;
- }
+ thread_unlock(td);
- /*
- * Do not swapout a process if it is
- * waiting on a critical event of some
- * kind or there is a thread whose
- * pageable memory may be accessed.
- *
- * This could be refined to support
- * swapping out a thread.
- */
- if (!thread_safetoswapout(td)) {
- thread_unlock(td);
- goto nextproc;
- }
- /*
- * If the system is under memory stress,
- * or if we are swapping
- * idle processes >= swap_idle_threshold2,
- * then swap the process out.
- */
- if ((action & VM_SWAP_NORMAL) == 0 &&
- ((action & VM_SWAP_IDLE) == 0 ||
- slptime < swap_idle_threshold2)) {
- thread_unlock(td);
- goto nextproc;
- }
+ if (!doswap)
+ break;
+ else if (minslptime > slptime)
+ minslptime = slptime;
+ }
- if (minslptime > slptime)
- minslptime = slptime;
- thread_unlock(td);
- }
+ /*
+ * If the pageout daemon didn't free enough pages,
+ * or if this process is idle and the system is
+ * configured to swap proactively, swap it out.
+ */
+ if (doswap && ((action & VM_SWAP_NORMAL) != 0 ||
+ ((action & VM_SWAP_IDLE) != 0 &&
+ minslptime > swap_idle_threshold2)) &&
+ swapout(p) == 0)
+ didswap = true;
- /*
- * If the pageout daemon didn't free enough pages,
- * or if this process is idle and the system is
- * configured to swap proactively, swap it out.
- */
- if ((action & VM_SWAP_NORMAL) != 0 ||
- ((action & VM_SWAP_IDLE) != 0 &&
- minslptime > swap_idle_threshold2)) {
- _PRELE(p);
- if (swapout(p) == 0)
- didswap = true;
- PROC_UNLOCK(p);
- goto retry;
- }
- }
-nextproc:
+ /*
+ * Hold on the process prevents its exit. The
+ * iteration, which dereferences p->p_list, can safely
+ * continue after the allproc_lock is reacquired.
+ */
PROC_UNLOCK(p);
sx_slock(&allproc_lock);
PRELE(p);
}
sx_sunlock(&allproc_lock);
+
/*
* If we swapped something out, and another process needed memory,
* then wakeup the sched process.

File Metadata

Mime Type
text/plain
Expires
Fri, Nov 28, 10:49 PM (11 h, 9 m)
Storage Engine
blob
Storage Format
Raw Data
Storage Handle
26306740
Default Alt Text
D13693.id37245.diff (4 KB)

Event Timeline