From: drh <drh@noemail.net>
Date: Fri, 12 Sep 2014 20:30:59 +0000 (+0000)
Subject: Small performance improvement to the dirty list handling in the pager.
X-Git-Tag: version-3.8.7~115
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=36ce91913c7923e06f1b6cdb8385812fd0fe9998;p=thirdparty%2Fsqlite.git

Small performance improvement to the dirty list handling in the pager.

FossilOrigin-Name: b332a84d5154f70f3197537df4af243eaebbb011
---

diff --git a/manifest b/manifest
index 8501d7bcd0..81daedebde 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Simplify\sthe\sway\sthe\scolumn\scache\sis\smanaged\saround\sOP_Move\sinstructions.
-D 2014-09-12T17:41:30.440
+C Small\sperformance\simprovement\sto\sthe\sdirty\slist\shandling\sin\sthe\spager.
+D 2014-09-12T20:30:59.762
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in cf57f673d77606ab0f2d9627ca52a9ba1464146a
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -217,7 +217,7 @@ F src/os_win.h 09e751b20bbc107ffbd46e13555dc73576d88e21
 F src/pager.c c6c809987f0c6a4e27634099d062d425527de173
 F src/pager.h ffd5607f7b3e4590b415b007a4382f693334d428
 F src/parse.y 22d6a074e5f5a7258947a1dc55a9bf946b765dd0
-F src/pcache.c 2048affdb09a04478b5fc6e64cb1083078d369be
+F src/pcache.c b42c513da255c33e99dc0e23d16c3caf30dc9175
 F src/pcache.h 9b559127b83f84ff76d735c8262f04853be0c59a
 F src/pcache1.c dab8ab930d4a73b99768d881185994f34b80ecaa
 F src/pragma.c 3f3e959390a10c0131676f0e307acce372777e0f
@@ -1197,7 +1197,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 2f69a1fa6adc9377149ae7faa586a5d30b6a631b
-R 2196198b201612a018f7c15a4c2f1424
+P 320556233e19cdd9d590a09655c3465754700d39
+R 576d19acba6677524711080ef6f39102
 U drh
-Z a609740927532bd8f27cb3bc904eb4ff
+Z 60cbf2357ae42b4a38f44133d16be246
diff --git a/manifest.uuid b/manifest.uuid
index 2b28a6b8f4..7821ed52ba 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-320556233e19cdd9d590a09655c3465754700d39
\ No newline at end of file
+b332a84d5154f70f3197537df4af243eaebbb011
\ No newline at end of file
diff --git a/src/pcache.c b/src/pcache.c
index 801df2b02a..e975e43889 100644
--- a/src/pcache.c
+++ b/src/pcache.c
@@ -116,14 +116,14 @@ static void pcacheManageDirtyList(PgHdr *pPage, u8 addRemove){
     if( pPage->pDirtyNext ){
       assert( pPage->pDirtyNext->pDirtyPrev==0 );
       pPage->pDirtyNext->pDirtyPrev = pPage;
-    }else if( p->bPurgeable ){
-      assert( p->eCreate==2 );
-      p->eCreate = 1;
-    }
-    p->pDirty = pPage;
-    if( !p->pDirtyTail ){
+    }else{
       p->pDirtyTail = pPage;
+      if( p->bPurgeable ){
+        assert( p->eCreate==2 );
+        p->eCreate = 1;
+      }
     }
+    p->pDirty = pPage;
     if( !p->pSynced && 0==(pPage->flags&PGHDR_NEED_SYNC) ){
       p->pSynced = pPage;
     }
@@ -399,7 +399,7 @@ void SQLITE_NOINLINE sqlite3PcacheRelease(PgHdr *p){
     p->pCache->nRef--;
     if( (p->flags&PGHDR_DIRTY)==0 ){
       pcacheUnpin(p);
-    }else{
+    }else if( p->pDirtyPrev!=0 ){
       /* Move the page to the head of the dirty list. */
       pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT);
     }