From: mpi Date: Mon, 22 Aug 2022 12:03:32 +0000 (+0000) Subject: Simplify locking by using an intermediate lock variable. X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=0dea91ce81ba26e05986afcd3518a761bdb998e2;p=openbsd Simplify locking by using an intermediate lock variable. While here get rid of the unused returned value of uvmpd_scan_inactive(). ok jsg@, kn@ --- diff --git a/sys/uvm/uvm_pdaemon.c b/sys/uvm/uvm_pdaemon.c index 52baa2eb590..020ee69caaf 100644 --- a/sys/uvm/uvm_pdaemon.c +++ b/sys/uvm/uvm_pdaemon.c @@ -1,4 +1,4 @@ -/* $OpenBSD: uvm_pdaemon.c,v 1.101 2022/06/28 19:31:30 mpi Exp $ */ +/* $OpenBSD: uvm_pdaemon.c,v 1.102 2022/08/22 12:03:32 mpi Exp $ */ /* $NetBSD: uvm_pdaemon.c,v 1.23 2000/08/20 10:24:14 bjh21 Exp $ */ /* @@ -102,7 +102,7 @@ extern void drmbackoff(long); */ void uvmpd_scan(struct uvm_pmalloc *); -boolean_t uvmpd_scan_inactive(struct uvm_pmalloc *, struct pglist *); +void uvmpd_scan_inactive(struct uvm_pmalloc *, struct pglist *); void uvmpd_tune(void); void uvmpd_drop(struct pglist *); @@ -377,17 +377,16 @@ uvm_aiodone_daemon(void *arg) * => we handle the building of swap-backed clusters * => we return TRUE if we are exiting because we met our target */ - -boolean_t +void uvmpd_scan_inactive(struct uvm_pmalloc *pma, struct pglist *pglst) { - boolean_t retval = FALSE; /* assume we haven't hit target */ int free, result; struct vm_page *p, *nextpg; struct uvm_object *uobj; struct vm_page *pps[SWCLUSTPAGES], **ppsp; int npages; struct vm_page *swpps[SWCLUSTPAGES]; /* XXX: see below */ + struct rwlock *slock; int swnpages, swcpages; /* XXX: see below */ int swslot; struct vm_anon *anon; @@ -402,7 +401,6 @@ uvmpd_scan_inactive(struct uvm_pmalloc *pma, struct pglist *pglst) */ swslot = 0; swnpages = swcpages = 0; - free = 0; dirtyreacts = 0; p = NULL; @@ -431,18 +429,14 @@ uvmpd_scan_inactive(struct uvm_pmalloc *pma, struct pglist *pglst) */ uobj = NULL; anon = NULL; - if (p) { /* - * update our copy of "free" and see if we've met - * our target + * see if we've met our target */ free = uvmexp.free - BUFPAGES_DEFICIT; if (((pma == NULL || (pma->pm_flags & UVM_PMA_FREED)) && (free + uvmexp.paging >= uvmexp.freetarg << 2)) || dirtyreacts == UVMPD_NUMDIRTYREACTS) { - retval = TRUE; - if (swslot == 0) { /* exit now if no swap-i/o pending */ break; @@ -450,9 +444,9 @@ uvmpd_scan_inactive(struct uvm_pmalloc *pma, struct pglist *pglst) /* set p to null to signal final swap i/o */ p = NULL; + nextpg = NULL; } } - if (p) { /* if (we have a new page to consider) */ /* * we are below target and have a new page to consider. @@ -460,11 +454,12 @@ uvmpd_scan_inactive(struct uvm_pmalloc *pma, struct pglist *pglst) uvmexp.pdscans++; nextpg = TAILQ_NEXT(p, pageq); + anon = p->uanon; + uobj = p->uobject; if (p->pg_flags & PQ_ANON) { - anon = p->uanon; KASSERT(anon != NULL); - if (rw_enter(anon->an_lock, - RW_WRITE|RW_NOSLEEP)) { + slock = anon->an_lock; + if (rw_enter(slock, RW_WRITE|RW_NOSLEEP)) { /* lock failed, skip this page */ continue; } @@ -474,23 +469,20 @@ uvmpd_scan_inactive(struct uvm_pmalloc *pma, struct pglist *pglst) */ if (pmap_is_referenced(p)) { uvm_pageactivate(p); - rw_exit(anon->an_lock); + rw_exit(slock); uvmexp.pdreact++; continue; } if (p->pg_flags & PG_BUSY) { - rw_exit(anon->an_lock); + rw_exit(slock); uvmexp.pdbusy++; - /* someone else owns page, skip it */ continue; } uvmexp.pdanscan++; } else { - uobj = p->uobject; KASSERT(uobj != NULL); - if (rw_enter(uobj->vmobjlock, - RW_WRITE|RW_NOSLEEP)) { - /* lock failed, skip this page */ + slock = uobj->vmobjlock; + if (rw_enter(slock, RW_WRITE|RW_NOSLEEP)) { continue; } /* @@ -499,14 +491,13 @@ uvmpd_scan_inactive(struct uvm_pmalloc *pma, struct pglist *pglst) */ if (pmap_is_referenced(p)) { uvm_pageactivate(p); - rw_exit(uobj->vmobjlock); + rw_exit(slock); uvmexp.pdreact++; continue; } if (p->pg_flags & PG_BUSY) { - rw_exit(uobj->vmobjlock); + rw_exit(slock); uvmexp.pdbusy++; - /* someone else owns page, skip it */ continue; } uvmexp.pdobscan++; @@ -539,10 +530,8 @@ uvmpd_scan_inactive(struct uvm_pmalloc *pma, struct pglist *pglst) /* remove from object */ anon->an_page = NULL; - rw_exit(anon->an_lock); - } else { - rw_exit(uobj->vmobjlock); } + rw_exit(slock); continue; } @@ -552,11 +541,7 @@ uvmpd_scan_inactive(struct uvm_pmalloc *pma, struct pglist *pglst) */ if ((pma == NULL || (pma->pm_flags & UVM_PMA_FREED)) && (free + uvmexp.paging > uvmexp.freetarg << 2)) { - if (anon) { - rw_exit(anon->an_lock); - } else { - rw_exit(uobj->vmobjlock); - } + rw_exit(slock); continue; } @@ -569,11 +554,7 @@ uvmpd_scan_inactive(struct uvm_pmalloc *pma, struct pglist *pglst) if ((p->pg_flags & PQ_SWAPBACKED) && uvm_swapisfull()) { dirtyreacts++; uvm_pageactivate(p); - if (anon) { - rw_exit(anon->an_lock); - } else { - rw_exit(uobj->vmobjlock); - } + rw_exit(slock); continue; } @@ -640,11 +621,7 @@ uvmpd_scan_inactive(struct uvm_pmalloc *pma, struct pglist *pglst) &p->pg_flags, PG_BUSY); UVM_PAGE_OWN(p, NULL); - if (anon) - rw_exit(anon->an_lock); - else - rw_exit( - uobj->vmobjlock); + rw_exit(slock); continue; } swcpages = 0; /* cluster is empty */ @@ -676,10 +653,7 @@ uvmpd_scan_inactive(struct uvm_pmalloc *pma, struct pglist *pglst) */ if (swap_backed) { if (p) { /* if we just added a page to cluster */ - if (anon) - rw_exit(anon->an_lock); - else - rw_exit(uobj->vmobjlock); + rw_exit(slock); /* cluster not full yet? */ if (swcpages < swnpages) @@ -791,10 +765,7 @@ uvmpd_scan_inactive(struct uvm_pmalloc *pma, struct pglist *pglst) /* !swap_backed case: already locked... */ if (swap_backed) { - if (anon) - rw_enter(anon->an_lock, RW_WRITE); - else - rw_enter(uobj->vmobjlock, RW_WRITE); + rw_enter(slock, RW_WRITE); } #ifdef DIAGNOSTIC @@ -855,10 +826,7 @@ uvmpd_scan_inactive(struct uvm_pmalloc *pma, struct pglist *pglst) * the inactive queue can't be re-queued [note: not * true for active queue]). */ - if (anon) - rw_exit(anon->an_lock); - else if (uobj) - rw_exit(uobj->vmobjlock); + rw_exit(slock); if (nextpg && (nextpg->pg_flags & PQ_INACTIVE) == 0) { nextpg = TAILQ_FIRST(pglst); /* reload! */ @@ -877,7 +845,6 @@ uvmpd_scan_inactive(struct uvm_pmalloc *pma, struct pglist *pglst) uvm_lock_pageq(); } } - return (retval); } /* @@ -925,10 +892,6 @@ uvmpd_scan(struct uvm_pmalloc *pma) * to inactive ones. */ - /* - * alternate starting queue between swap and object based on the - * low bit of uvmexp.pdrevs (which we bump by one each call). - */ pages_freed = uvmexp.pdfreed; (void) uvmpd_scan_inactive(pma, &uvm.page_inactive); pages_freed = uvmexp.pdfreed - pages_freed;