From d6f9a991c6690168c2012037cb4e71840917f2a6 Mon Sep 17 00:00:00 2001
From: rwatson <rwatson@FreeBSD.org>
Date: Wed, 10 Jan 2007 21:04:43 +0000
Subject: [PATCH] Remove uma_zalloc_arg() hack, which coerced M_WAITOK to
 M_NOWAIT when allocations were made using improper flags in interrupt
 context. Replace with a simple WITNESS warning call.  This restores the
 invariant that M_WAITOK allocations will always succeed or die horribly
 trying, which is relied on by many UMA consumers.

MFC after:	3 weeks
Discussed with:	jhb
---
 sys/vm/uma_core.c | 25 +++----------------------
 1 file changed, 3 insertions(+), 22 deletions(-)

diff --git a/sys/vm/uma_core.c b/sys/vm/uma_core.c
index ac3ffc425d6a..0bdcd2fbc8fe 100644
--- a/sys/vm/uma_core.c
+++ b/sys/vm/uma_core.c
@@ -1772,7 +1772,6 @@ uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
 	uma_cache_t cache;
 	uma_bucket_t bucket;
 	int cpu;
-	int badness;
 
 	/* This is the fast path allocation */
 #ifdef UMA_DEBUG_ALLOC_1
@@ -1781,27 +1780,9 @@ uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
 	CTR3(KTR_UMA, "uma_zalloc_arg thread %x zone %s flags %d", curthread,
 	    zone->uz_name, flags);
 
-	if (!(flags & M_NOWAIT)) {
-		KASSERT(curthread->td_intr_nesting_level == 0,
-		   ("malloc(M_WAITOK) in interrupt context"));
-		if (nosleepwithlocks) {
-#ifdef WITNESS
-			badness = WITNESS_CHECK(WARN_GIANTOK | WARN_SLEEPOK,
-			    NULL,
-			    "malloc(M_WAITOK) of \"%s\", forcing M_NOWAIT",
-			    zone->uz_name);
-#else
-			badness = 1;
-#endif
-		} else {
-			badness = 0;
-			WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
-			    "malloc(M_WAITOK) of \"%s\"", zone->uz_name);
-		}
-		if (badness) {
-			flags &= ~M_WAITOK;
-			flags |= M_NOWAIT;
-		}
+	if (flags & M_WAITOK) {
+		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
+		    "uma_zalloc_arg: zone \"%s\"", zone->uz_name);
 	}
 
 	/*