* Eric Dumazet <[EMAIL PROTECTED]> wrote:

> Please test that len is a constant, or else the inlining is too large 
> for the non constant case.

yeah. fix below.

        Ingo

-----
noticed by Eric Dumazet: unrolling should be dependent on a constant
length, otherwise inlining gets too large.

Signed-off-by: Ingo Molnar <[EMAIL PROTECTED]>

 include/linux/prefetch.h |  128 ++++++++++++++++++++++++-----------------------
 1 files changed, 66 insertions(+), 62 deletions(-)

Index: linux-prefetch-task/include/linux/prefetch.h
===================================================================
--- linux-prefetch-task.orig/include/linux/prefetch.h
+++ linux-prefetch-task/include/linux/prefetch.h
@@ -64,37 +64,39 @@ static inline void prefetch_range(void *
        /*
         * Unroll agressively:
         */
-       if (len <= PREFETCH_STRIDE)
-               prefetch(cp);
-       else if (len <= 2*PREFETCH_STRIDE) {
-               prefetch(cp);
-               prefetch(cp + PREFETCH_STRIDE);
-       }
-       else if (len <= 3*PREFETCH_STRIDE) {
-               prefetch(cp);
-               prefetch(cp + PREFETCH_STRIDE);
-               prefetch(cp + 2*PREFETCH_STRIDE);
-       }
-       else if (len <= 4*PREFETCH_STRIDE) {
-               prefetch(cp);
-               prefetch(cp + PREFETCH_STRIDE);
-               prefetch(cp + 2*PREFETCH_STRIDE);
-               prefetch(cp + 3*PREFETCH_STRIDE);
-       }
-       else if (len <= 5*PREFETCH_STRIDE) {
-               prefetch(cp);
-               prefetch(cp + PREFETCH_STRIDE);
-               prefetch(cp + 2*PREFETCH_STRIDE);
-               prefetch(cp + 3*PREFETCH_STRIDE);
-               prefetch(cp + 4*PREFETCH_STRIDE);
-       }
-       else if (len <= 6*PREFETCH_STRIDE) {
-               prefetch(cp);
-               prefetch(cp + PREFETCH_STRIDE);
-               prefetch(cp + 2*PREFETCH_STRIDE);
-               prefetch(cp + 3*PREFETCH_STRIDE);
-               prefetch(cp + 4*PREFETCH_STRIDE);
-               prefetch(cp + 5*PREFETCH_STRIDE);
+       if (__builtin_constant_p(len) && (len <= 6*PREFETCH_STRIDE)) {
+               if (len <= PREFETCH_STRIDE)
+                       prefetch(cp);
+               else if (len <= 2*PREFETCH_STRIDE) {
+                       prefetch(cp);
+                       prefetch(cp + PREFETCH_STRIDE);
+               }
+               else if (len <= 3*PREFETCH_STRIDE) {
+                       prefetch(cp);
+                       prefetch(cp + PREFETCH_STRIDE);
+                       prefetch(cp + 2*PREFETCH_STRIDE);
+               }
+               else if (len <= 4*PREFETCH_STRIDE) {
+                       prefetch(cp);
+                       prefetch(cp + PREFETCH_STRIDE);
+                       prefetch(cp + 2*PREFETCH_STRIDE);
+                       prefetch(cp + 3*PREFETCH_STRIDE);
+               }
+               else if (len <= 5*PREFETCH_STRIDE) {
+                       prefetch(cp);
+                       prefetch(cp + PREFETCH_STRIDE);
+                       prefetch(cp + 2*PREFETCH_STRIDE);
+                       prefetch(cp + 3*PREFETCH_STRIDE);
+                       prefetch(cp + 4*PREFETCH_STRIDE);
+               }
+               else if (len <= 6*PREFETCH_STRIDE) {
+                       prefetch(cp);
+                       prefetch(cp + PREFETCH_STRIDE);
+                       prefetch(cp + 2*PREFETCH_STRIDE);
+                       prefetch(cp + 3*PREFETCH_STRIDE);
+                       prefetch(cp + 4*PREFETCH_STRIDE);
+                       prefetch(cp + 5*PREFETCH_STRIDE);
+               }
        } else
                for (; cp < end; cp += PREFETCH_STRIDE)
                        prefetch(cp);
@@ -110,37 +112,39 @@ static inline void prefetchw_range(void 
        /*
         * Unroll agressively:
         */
-       if (len <= PREFETCH_STRIDE)
-               prefetchw(cp);
-       else if (len <= 2*PREFETCH_STRIDE) {
-               prefetchw(cp);
-               prefetchw(cp + PREFETCH_STRIDE);
-       }
-       else if (len <= 3*PREFETCH_STRIDE) {
-               prefetchw(cp);
-               prefetchw(cp + PREFETCH_STRIDE);
-               prefetchw(cp + 2*PREFETCH_STRIDE);
-       }
-       else if (len <= 4*PREFETCH_STRIDE) {
-               prefetchw(cp);
-               prefetchw(cp + PREFETCH_STRIDE);
-               prefetchw(cp + 2*PREFETCH_STRIDE);
-               prefetchw(cp + 3*PREFETCH_STRIDE);
-       }
-       else if (len <= 5*PREFETCH_STRIDE) {
-               prefetchw(cp);
-               prefetchw(cp + PREFETCH_STRIDE);
-               prefetchw(cp + 2*PREFETCH_STRIDE);
-               prefetchw(cp + 3*PREFETCH_STRIDE);
-               prefetchw(cp + 4*PREFETCH_STRIDE);
-       }
-       else if (len <= 6*PREFETCH_STRIDE) {
-               prefetchw(cp);
-               prefetchw(cp + PREFETCH_STRIDE);
-               prefetchw(cp + 2*PREFETCH_STRIDE);
-               prefetchw(cp + 3*PREFETCH_STRIDE);
-               prefetchw(cp + 4*PREFETCH_STRIDE);
-               prefetchw(cp + 5*PREFETCH_STRIDE);
+       if (__builtin_constant_p(len) && (len <= 6*PREFETCH_STRIDE)) {
+               if (len <= PREFETCH_STRIDE)
+                       prefetchw(cp);
+               else if (len <= 2*PREFETCH_STRIDE) {
+                       prefetchw(cp);
+                       prefetchw(cp + PREFETCH_STRIDE);
+               }
+               else if (len <= 3*PREFETCH_STRIDE) {
+                       prefetchw(cp);
+                       prefetchw(cp + PREFETCH_STRIDE);
+                       prefetchw(cp + 2*PREFETCH_STRIDE);
+               }
+               else if (len <= 4*PREFETCH_STRIDE) {
+                       prefetchw(cp);
+                       prefetchw(cp + PREFETCH_STRIDE);
+                       prefetchw(cp + 2*PREFETCH_STRIDE);
+                       prefetchw(cp + 3*PREFETCH_STRIDE);
+               }
+               else if (len <= 5*PREFETCH_STRIDE) {
+                       prefetchw(cp);
+                       prefetchw(cp + PREFETCH_STRIDE);
+                       prefetchw(cp + 2*PREFETCH_STRIDE);
+                       prefetchw(cp + 3*PREFETCH_STRIDE);
+                       prefetchw(cp + 4*PREFETCH_STRIDE);
+               }
+               else if (len <= 6*PREFETCH_STRIDE) {
+                       prefetchw(cp);
+                       prefetchw(cp + PREFETCH_STRIDE);
+                       prefetchw(cp + 2*PREFETCH_STRIDE);
+                       prefetchw(cp + 3*PREFETCH_STRIDE);
+                       prefetchw(cp + 4*PREFETCH_STRIDE);
+                       prefetchw(cp + 5*PREFETCH_STRIDE);
+               }
        } else
                for (; cp < end; cp += PREFETCH_STRIDE)
                        prefetchw(cp);
-
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