xserver: Branch 'master'
Keith Packard
keithp at kemper.freedesktop.org
Fri Oct 28 16:29:20 UTC 2016
dix/resource.c | 33 +++++++++------------------------
1 file changed, 9 insertions(+), 24 deletions(-)
New commits:
commit c85f81825e196e96337347e0ce3a538fb2e38f16
Author: Keith Packard <keithp at keithp.com>
Date: Fri Oct 28 09:28:32 2016 -0700
dix: Bump MAXHASHSIZE for the resource db [v2]
[This was originally a workaround for a client-side resource leak:
http://lists.freedesktop.org/archives/xorg-devel/2012-November/034555.html
Obviously that's a broken app, but the performance problem it
illustrates - that walking the linked list ends up burning all your CPU
time - is real enough. - ajax]
v2: Replace with a shorter code sequence which computes the same
results for all but numBits == 7
Reviewed-by: Adam Jackson <ajax at redhat.com>
Signed-off-by: Keith Packard <keithp at keithp.com>
diff --git a/dix/resource.c b/dix/resource.c
index 68efd24..b6ef99f 100644
--- a/dix/resource.c
+++ b/dix/resource.c
@@ -156,7 +156,7 @@ static void RebuildTable(int /*client */
#define INITBUCKETS 64
#define INITHASHSIZE 6
-#define MAXHASHSIZE 11
+#define MAXHASHSIZE 16
typedef struct _Resource {
struct _Resource *next;
@@ -668,29 +668,14 @@ InitClientResources(ClientPtr client)
int
HashResourceID(XID id, int numBits)
{
- id &= RESOURCE_ID_MASK;
- switch (numBits)
- {
- case 6:
- return ((int)(0x03F & (id ^ (id>>6) ^ (id>>12))));
- case 7:
- return ((int)(0x07F & (id ^ (id>>7) ^ (id>>13))));
- case 8:
- return ((int)(0x0FF & (id ^ (id>>8) ^ (id>>16))));
- case 9:
- return ((int)(0x1FF & (id ^ (id>>9))));
- case 10:
- return ((int)(0x3FF & (id ^ (id>>10))));
- case 11:
- return ((int)(0x7FF & (id ^ (id>>11))));
- }
- if (numBits >= 11)
- return ((int)(0x7FF & (id ^ (id>>11))));
- else
- {
- assert(numBits >= 0);
- return id & ~((~0) << numBits);
- }
+ static XID mask;
+
+ if (!mask)
+ mask = RESOURCE_ID_MASK;
+ id &= mask;
+ if (numBits < 9)
+ return (id ^ (id >> numBits) ^ (id >> (numBits<<1))) & ~((~0) << numBits);
+ return (id ^ (id >> numBits)) & ~((~0) << numBits);
}
static XID
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