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Merge identical code paths to promote data to a new anon into a new function.

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ok tb@, miod@
This commit is contained in:
mpi 2024-12-20 18:46:51 +00:00
parent c7c5643a71
commit dceff77413
1 changed files with 71 additions and 73 deletions
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144
sys/uvm/uvm_fault.c
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@ -1,4 +1,4 @@
/* $OpenBSD: uvm_fault.c,v 1.154 2024/12/18 16:41:27 mpi Exp $ */
/* $OpenBSD: uvm_fault.c,v 1.155 2024/12/20 18:46:51 mpi Exp $ */
/* $NetBSD: uvm_fault.c,v 1.51 2000/08/06 00:22:53 thorpej Exp $ */
/*
@ -484,6 +484,68 @@ uvmfault_anonget(struct uvm_faultinfo *ufi, struct vm_amap *amap,
/*NOTREACHED*/
}
/*
* uvmfault_promote: promote data to a new anon. used for 1B and 2B.
*
* 1. allocate an anon and a page.
* 2. fill its contents.
*
* => if we fail (result != 0) we unlock everything.
* => on success, return a new locked anon via 'nanon'.
* => it's caller's responsibility to put the promoted nanon->an_page to the
* page queue.
*/
int
uvmfault_promote(struct uvm_faultinfo *ufi,
struct vm_page *uobjpage,
struct vm_anon **nanon, /* OUT: allocated anon */
struct vm_page **npg)
{
struct vm_amap *amap = ufi->entry->aref.ar_amap;
struct vm_anon *anon;
struct vm_page *pg = NULL;
anon = uvm_analloc();
if (anon) {
anon->an_lock = amap->am_lock;
pg = uvm_pagealloc(NULL, 0, anon,
(uobjpage == PGO_DONTCARE) ? UVM_PGA_ZERO : 0);
}
/* check for out of RAM */
if (anon == NULL || pg == NULL) {
uvmfault_unlockall(ufi, amap, NULL);
if (anon == NULL)
counters_inc(uvmexp_counters, flt_noanon);
else {
anon->an_lock = NULL;
anon->an_ref--;
uvm_anfree(anon);
counters_inc(uvmexp_counters, flt_noram);
}
if (uvm_swapisfull())
return ENOMEM;
/* out of RAM, wait for more */
if (anon == NULL)
uvm_anwait();
else
uvm_wait("flt_noram3");
return ERESTART;
}
/*
* copy the page [pg now dirty]
*/
if (uobjpage != PGO_DONTCARE)
uvm_pagecopy(uobjpage, pg);
*nanon = anon;
*npg = pg;
return 0;
}
/*
* Update statistics after fault resolution.
* - maxrss
@ -972,37 +1034,11 @@ uvm_fault_upper(struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
counters_inc(uvmexp_counters, flt_acow);
oanon = anon; /* oanon = old */
anon = uvm_analloc();
if (anon) {
anon->an_lock = amap->am_lock;
pg = uvm_pagealloc(NULL, 0, anon, 0);
}
/* check for out of RAM */
if (anon == NULL || pg == NULL) {
uvmfault_unlockall(ufi, amap, NULL);
if (anon == NULL)
counters_inc(uvmexp_counters, flt_noanon);
else {
anon->an_lock = NULL;
anon->an_ref--;
uvm_anfree(anon);
counters_inc(uvmexp_counters, flt_noram);
}
error = uvmfault_promote(ufi, oanon->an_page, &anon, &pg);
if (error)
return error;
if (uvm_swapisfull())
return ENOMEM;
/* out of RAM, wait for more */
if (anon == NULL)
uvm_anwait();
else
uvm_wait("flt_noram3");
return ERESTART;
}
/* got all resources, replace anon with nanon */
uvm_pagecopy(oanon->an_page, pg); /* pg now !PG_CLEAN */
/* un-busy! new page */
atomic_clearbits_int(&pg->pg_flags, PG_BUSY|PG_FAKE);
UVM_PAGE_OWN(pg, NULL);
@ -1314,53 +1350,15 @@ uvm_fault_lower(struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
if (amap == NULL)
panic("uvm_fault: want to promote data, but no anon");
#endif
anon = uvm_analloc();
if (anon) {
/*
* In `Fill in data...' below, if
* uobjpage == PGO_DONTCARE, we want
* a zero'd, dirty page, so have
* uvm_pagealloc() do that for us.
*/
anon->an_lock = amap->am_lock;
pg = uvm_pagealloc(NULL, 0, anon,
(uobjpage == PGO_DONTCARE) ? UVM_PGA_ZERO : 0);
}
/*
* out of memory resources?
*/
if (anon == NULL || pg == NULL) {
/* unlock and fail ... */
uvmfault_unlockall(ufi, amap, uobj);
if (anon == NULL)
counters_inc(uvmexp_counters, flt_noanon);
else {
anon->an_lock = NULL;
anon->an_ref--;
uvm_anfree(anon);
counters_inc(uvmexp_counters, flt_noram);
}
if (uvm_swapisfull())
return (ENOMEM);
/* out of RAM, wait for more */
if (anon == NULL)
uvm_anwait();
else
uvm_wait("flt_noram5");
return ERESTART;
}
error = uvmfault_promote(ufi, uobjpage, &anon, &pg);
if (error)
return error;
/*
* fill in the data
*/
if (uobjpage != PGO_DONTCARE) {
counters_inc(uvmexp_counters, flt_prcopy);
/* copy page [pg now dirty] */
uvm_pagecopy(uobjpage, pg);
/*
* promote to shared amap? make sure all sharing
@ -1388,8 +1386,8 @@ uvm_fault_lower(struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
} else {
counters_inc(uvmexp_counters, flt_przero);
/*
* Page is zero'd and marked dirty by uvm_pagealloc()
* above.
* Page is zero'd and marked dirty by uvm_pagealloc(),
* called in uvmfault_promote() above.
*/
}