Date: Thu, 30 Nov 2017 22:37:25 +0200 From: Konstantin Belousov <kostikbel@gmail.com> To: Larry McVoy <lm@mcvoy.com> Cc: Warner Losh <imp@bsdimp.com>, Scott Long <scottl@netflix.com>, Kevin Bowling <kbowling@llnw.com>, Drew Gallatin <gallatin@netflix.com>, "freebsd-arch@freebsd.org" <freebsd-arch@freebsd.org> Subject: Re: small patch for pageout. Comments? Message-ID: <20171130203725.GG2272@kib.kiev.ua> In-Reply-To: <20171130203047.GB30262@mcvoy.com> References: <20171130173424.GA811@mcvoy.com> <CANCZdfqL9ZsKTfFi%2BvsCTh3yaNjtwaYYY3fvivdbNybBnujawg@mail.gmail.com> <20171130184923.GA30262@mcvoy.com> <20171130193213.GF2272@kib.kiev.ua> <20171130203047.GB30262@mcvoy.com>
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On Thu, Nov 30, 2017 at 12:30:47PM -0800, Larry McVoy wrote:
> I'll give this patch a try and compare to the pageout patch.
What do you mean by 'compare to ...' ?
BTW, below are some fixes which I found when re-read the changes.
It messed up counters/timeouts. Better use this.
diff --git a/sys/vm/vm_fault.c b/sys/vm/vm_fault.c
index ece496407c2..48b3934ddd5 100644
--- a/sys/vm/vm_fault.c
+++ b/sys/vm/vm_fault.c
@@ -134,6 +134,16 @@ static void vm_fault_dontneed(const struct faultstate *fs, vm_offset_t vaddr,
static void vm_fault_prefault(const struct faultstate *fs, vm_offset_t addra,
int backward, int forward);
+static int vm_pfault_oom_attempts = 3;
+SYSCTL_INT(_vm, OID_AUTO, pfault_oom_attempts, CTLFLAG_RWTUN,
+ &vm_pfault_oom_attempts, 0,
+ "");
+
+static int vm_pfault_oom_wait = 10;
+SYSCTL_INT(_vm, OID_AUTO, pfault_oom_wait, CTLFLAG_RWTUN,
+ &vm_pfault_oom_wait, 0,
+ "");
+
static inline void
release_page(struct faultstate *fs)
{
@@ -531,7 +541,7 @@ vm_fault_hold(vm_map_t map, vm_offset_t vaddr, vm_prot_t fault_type,
vm_pindex_t retry_pindex;
vm_prot_t prot, retry_prot;
int ahead, alloc_req, behind, cluster_offset, error, era, faultcount;
- int locked, nera, result, rv;
+ int locked, nera, oom, result, rv;
u_char behavior;
boolean_t wired; /* Passed by reference. */
bool dead, hardfault, is_first_object_locked;
@@ -543,6 +553,8 @@ vm_fault_hold(vm_map_t map, vm_offset_t vaddr, vm_prot_t fault_type,
hardfault = false;
RetryFault:;
+ oom = 0;
+RetryFault_oom:;
/*
* Find the backing store object and offset into it to begin the
@@ -787,7 +799,17 @@ RetryFault:;
}
if (fs.m == NULL) {
unlock_and_deallocate(&fs);
- VM_WAITPFAULT;
+ if (vm_pfault_oom_attempts < 0 ||
+ oom < vm_pfault_oom_attempts) {
+ oom++;
+ vm_waitpfault(vm_pfault_oom_wait);
+ goto RetryFault_oom;
+ }
+ if (bootverbose)
+ printf(
+ "proc %d (%s) failed to alloc page on fault, starting OOM\n",
+ curproc->p_pid, curproc->p_comm);
+ vm_pageout_oom(VM_OOM_MEM);
goto RetryFault;
}
}
diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index 4711af9d16d..67c8ddd4b92 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -2724,7 +2724,7 @@ vm_page_alloc_fail(vm_object_t object, int req)
* this balance without careful testing first.
*/
void
-vm_waitpfault(void)
+vm_waitpfault(int wp)
{
mtx_lock(&vm_page_queue_free_mtx);
@@ -2734,7 +2734,7 @@ vm_waitpfault(void)
}
vm_pages_needed = true;
msleep(&vm_cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PUSER,
- "pfault", 0);
+ "pfault", wp * hz);
}
struct vm_pagequeue *
diff --git a/sys/vm/vm_pageout.h b/sys/vm/vm_pageout.h
index 2cdb1492fab..bf09d7142d0 100644
--- a/sys/vm/vm_pageout.h
+++ b/sys/vm/vm_pageout.h
@@ -96,11 +96,10 @@ extern bool vm_pages_needed;
* Signal pageout-daemon and wait for it.
*/
-extern void pagedaemon_wakeup(void);
+void pagedaemon_wakeup(void);
#define VM_WAIT vm_wait()
-#define VM_WAITPFAULT vm_waitpfault()
-extern void vm_wait(void);
-extern void vm_waitpfault(void);
+void vm_wait(void);
+void vm_waitpfault(int wp);
#ifdef _KERNEL
int vm_pageout_flush(vm_page_t *, int, int, int, int *, boolean_t *);
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