svn commit: r312714 - in stable/11/sys: kern sys vm

[Mateusz Guzik]

Author: mjg
Date: Tue Jan 24 19:39:24 2017
New Revision: 312714
URL: https://svnweb.freebsd.org/changeset/base/312714

Log:
  MFC r310805:
  
      Remove cpu_spinwait after seq_consistent.
  
      It does not add any benefit as the read routine will do it as necessary.

Modified:
  stable/11/sys/kern/kern_descrip.c
  stable/11/sys/sys/seq.h
  stable/11/sys/vm/vm_domain.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/kern/kern_descrip.c
==============================================================================
--- stable/11/sys/kern/kern_descrip.c	Tue Jan 24 19:38:10 2017	(r312713)
+++ stable/11/sys/kern/kern_descrip.c	Tue Jan 24 19:39:24 2017	(r312714)
@@ -2477,10 +2477,8 @@ fget_unlocked(struct filedesc *fdp, int 
 		fde = &fdt->fdt_ofiles[fd];
 		haverights = *cap_rights_fde(fde);
 		fp = fde->fde_file;
-		if (!seq_consistent(fd_seq(fdt, fd), seq)) {
-			cpu_spinwait();
+		if (!seq_consistent(fd_seq(fdt, fd), seq))
 			continue;
-		}
 #else
 		fp = fdt->fdt_ofiles[fd].fde_file;
 #endif

Modified: stable/11/sys/sys/seq.h
==============================================================================
--- stable/11/sys/sys/seq.h	Tue Jan 24 19:38:10 2017	(r312713)
+++ stable/11/sys/sys/seq.h	Tue Jan 24 19:39:24 2017	(r312714)
@@ -59,7 +59,6 @@ typedef uint32_t seq_t;
  * 		lobj = gobj;
  * 		if (seq_consistent(&gobj->seq, seq))
  * 			break;
- * 		cpu_spinwait();
  * 	}
  * 	foo(lobj);
  */		

Modified: stable/11/sys/vm/vm_domain.c
==============================================================================
--- stable/11/sys/vm/vm_domain.c	Tue Jan 24 19:38:10 2017	(r312713)
+++ stable/11/sys/vm/vm_domain.c	Tue Jan 24 19:39:24 2017	(r312714)
@@ -140,7 +140,6 @@ vm_domain_policy_localcopy(struct vm_dom
 		*dst = *src;
 		if (seq_consistent(&src->seq, seq))
 			return;
-		cpu_spinwait();
 	}
 }
 
@@ -168,7 +167,6 @@ vm_domain_policy_copy(struct vm_domain_p
 			seq_write_end(&dst->seq);
 			return;
 		}
-		cpu_spinwait();
 	}
 }
 
@@ -330,7 +328,6 @@ vm_domain_iterator_set_policy(struct vm_
 			_vm_domain_iterator_set_policy(vi, &vt_lcl);
 			return;
 		}
-		cpu_spinwait();
 	}
 }