From: Oliver Kurth <okurth@vmware.com>
Date: Fri, 15 Sep 2017 18:23:23 +0000 (-0700)
Subject: lib/poll: Trim PollClassSet
X-Git-Tag: stable-10.2.0~363
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=4a8aecf2d148ce11afbad939beb7b629a8970263;p=thirdparty%2Fopen-vm-tools.git

lib/poll: Trim PollClassSet

We no longer need per-VCPU poll classes, trim PollClassSet down to
a non-array size.

Tweak a few pollInt.h algorithms so that compile-time-constant
PollClass values can be constant-folded.
---

diff --git a/open-vm-tools/lib/include/poll.h b/open-vm-tools/lib/include/poll.h
index 75d221a09..67297ede2 100644
--- a/open-vm-tools/lib/include/poll.h
+++ b/open-vm-tools/lib/include/poll.h
@@ -108,7 +108,7 @@ typedef enum PollClass {
    POLL_CLASS_MKS,
    POLL_FIXED_CLASSES,
    /* Size enum to maximum */
-   POLL_MAX_CLASSES = 540,
+   POLL_MAX_CLASSES = 31,
 } PollClass;
 
 
@@ -117,16 +117,14 @@ typedef enum PollClass {
  */
 
 typedef struct PollClassSet {
-   /* Type is uintptr_t to give best 32/64-bit code. */
-#define _POLL_ELEMSIZE (sizeof (uintptr_t) * 8)
-   uintptr_t bits[CEILING(POLL_MAX_CLASSES, _POLL_ELEMSIZE)];
+   uintptr_t bits;
 } PollClassSet;
 
 /* An empty PollClassSet. */
 static INLINE PollClassSet
 PollClassSet_Empty(void)
 {
-   PollClassSet set = { { 0 } };
+   PollClassSet set = { 0 };
    return set;
 }
 
@@ -136,12 +134,10 @@ PollClassSet_Singleton(PollClass c)
 {
    PollClassSet s = PollClassSet_Empty();
 
-   ASSERT_ON_COMPILE(sizeof s.bits[0] * 8 == _POLL_ELEMSIZE); /* Size correct */
-   ASSERT_ON_COMPILE((_POLL_ELEMSIZE & (_POLL_ELEMSIZE - 1)) == 0); /* power of 2 */
-   ASSERT_ON_COMPILE(POLL_MAX_CLASSES <= ARRAYSIZE(s.bits) * _POLL_ELEMSIZE);
+   ASSERT_ON_COMPILE(POLL_MAX_CLASSES < sizeof s.bits * 8);
    ASSERT(c < POLL_MAX_CLASSES);
 
-   s.bits[c / _POLL_ELEMSIZE] = CONST3264U(1) << (c % _POLL_ELEMSIZE);
+   s.bits = CONST3264U(1) << c;
    return s;
 }
 
@@ -149,13 +145,9 @@ PollClassSet_Singleton(PollClass c)
 static INLINE PollClassSet
 PollClassSet_Union(PollClassSet lhs, PollClassSet rhs)
 {
-   PollClassSet u;
-   unsigned i;
-
-   for (i = 0; i < ARRAYSIZE(u.bits); i++) {
-      u.bits[i] = lhs.bits[i] | rhs.bits[i];
-   }
-   return u;
+   PollClassSet set;
+   set.bits = lhs.bits | rhs.bits;
+   return set;
 }
 
 /* Add single class to PollClassSet. */
diff --git a/open-vm-tools/lib/include/pollImpl.h b/open-vm-tools/lib/include/pollImpl.h
index 2a5b1edfa..366f8a2ea 100644
--- a/open-vm-tools/lib/include/pollImpl.h
+++ b/open-vm-tools/lib/include/pollImpl.h
@@ -45,6 +45,7 @@
 #include "includeCheck.h"
 
 #include "poll.h"
+#include "vm_basic_asm.h"
 
 #if defined(__cplusplus)
 extern "C" {
@@ -84,22 +85,14 @@ void Poll_InitWithImpl(const PollImpl *impl);
 static INLINE Bool
 PollClassSet_IsMember(PollClassSet set, PollClass c)
 {
-   ASSERT(c < POLL_MAX_CLASSES);
-   return ((set.bits[c / _POLL_ELEMSIZE] >> (c % _POLL_ELEMSIZE)) & 0x1) != 0;
+   return (set.bits & PollClassSet_Singleton(c).bits) != 0;
 }
 
 /* Compare two PollClassSets. */
 static INLINE Bool
 PollClassSet_Equals(PollClassSet lhs, PollClassSet rhs)
 {
-   unsigned i;
-
-   for (i = 0; i < ARRAYSIZE(lhs.bits); i++) {
-      if (lhs.bits[i] != rhs.bits[i]) {
-         return FALSE;
-      }
-   }
-   return TRUE;
+   return lhs.bits == rhs.bits;
 }
 
 /* Verifies if the class set is empty. */
@@ -113,27 +106,15 @@ PollClassSet_IsEmpty(PollClassSet cs)
 static INLINE void
 PollClassSet_Remove(PollClassSet *set, PollClass c)
 {
-   ASSERT(c < POLL_MAX_CLASSES);
-   set->bits[c / _POLL_ELEMSIZE] &= ~(CONST3264U(1) << (c % _POLL_ELEMSIZE));
+   set->bits &= ~PollClassSet_Singleton(c).bits;
 }
 
 /* Find first set.  POLL_MAX_CLASSES for none set. */
 static INLINE PollClass
 PollClassSet_FFS(PollClassSet *set)
 {
-   unsigned i, j;
-
-   /* XXX TODO: use lssbPtr */
-   for (i = 0; i < ARRAYSIZE(set->bits); i++) {
-      if (set->bits[i] != 0) {
-         for (j = 0; j < _POLL_ELEMSIZE; j++) {
-            if ((set->bits[i] & (CONST3264U(1) << j)) != 0) {
-               PollClass c = (PollClass)(i * _POLL_ELEMSIZE + j);
-               ASSERT(c < POLL_MAX_CLASSES);
-               return c;
-            }
-         }
-      }
+   if (set->bits != 0) {
+      return lssbPtr_0(set->bits);
    }
    return POLL_MAX_CLASSES;
 }