The patch titled
random: remove some prefetch logic
has been added to the -mm tree. Its filename is
random-remove-some-prefetch-logic.patch
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The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: random: remove some prefetch logic
From: Matt Mackall <mpm@xxxxxxxxxxx>
The urandom output pool (ie the fast path) fits in one cacheline, so
this is pretty unnecessary. Further, the output path has already
fetched the entire pool to hash it before calling in here.
(This was the only user of prefetch_range in the kernel, and it passed
in words rather than bytes!)
Signed-off-by: Matt Mackall <mpm@xxxxxxxxxxx>
Cc: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/char/random.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff -puN drivers/char/random.c~random-remove-some-prefetch-logic drivers/char/random.c
--- a/drivers/char/random.c~random-remove-some-prefetch-logic
+++ a/drivers/char/random.c
@@ -457,7 +457,7 @@ static void __add_entropy_words(struct e
unsigned long i, add_ptr, tap1, tap2, tap3, tap4, tap5;
int input_rotate;
int wordmask = r->poolinfo->poolwords - 1;
- __u32 w, next_w;
+ __u32 w;
unsigned long flags;
/* Taps are constant, so we can load them without holding r->lock. */
@@ -466,17 +466,13 @@ static void __add_entropy_words(struct e
tap3 = r->poolinfo->tap3;
tap4 = r->poolinfo->tap4;
tap5 = r->poolinfo->tap5;
- next_w = *in++;
spin_lock_irqsave(&r->lock, flags);
- prefetch_range(r->pool, wordmask);
input_rotate = r->input_rotate;
add_ptr = r->add_ptr;
while (nwords--) {
- w = rol32(next_w, input_rotate & 31);
- if (nwords > 0)
- next_w = *in++;
+ w = rol32(*in++, input_rotate & 31);
i = add_ptr = (add_ptr - 1) & wordmask;
/* XOR in the various taps */
_
Patches currently in -mm which might be from mpm@xxxxxxxxxxx are
git-x86.patch
maps4-add-proportional-set-size-accounting-in-smaps.patch
maps4-rework-task_size-macros.patch
maps4-rework-task_size-macros-mips-fix.patch
maps4-move-is_swap_pte.patch
maps4-introduce-a-generic-page-walker.patch
maps4-use-pagewalker-in-clear_refs-and-smaps.patch
maps4-simplify-interdependence-of-maps-and-smaps.patch
maps4-move-clear_refs-code-to-task_mmuc.patch
maps4-regroup-task_mmu-by-interface.patch
maps4-add-proc-pid-pagemap-interface.patch
maps4-add-proc-pid-pagemap-interface-fix.patch
maps4-add-proc-kpagecount-interface.patch
maps4-add-proc-kpagecount-interface-fix.patch
maps4-add-proc-kpageflags-interface.patch
maps4-add-proc-kpageflags-interface-fix.patch
maps4-add-proc-kpageflags-interface-fix-2.patch
maps4-add-proc-kpageflags-interface-fix-2-fix.patch
maps4-make-page-monitoring-proc-file-optional.patch
maps4-make-page-monitoring-proc-file-optional-fix.patch
remove-unused-code-from-mm-tiny-shmemc.patch
drivers-char-randomcwrite_pool-cond_resched-needed.patch
random-clean-up-checkpatch-complaints.patch
random-consolidate-wakeup-logic.patch
random-use-unlocked_ioctl.patch
random-reuse-rand_initialize.patch
random-improve-variable-naming-clear-extract-buffer.patch
random-make-backtracking-attacks-harder.patch
random-remove-cacheline-alignment-for-locks.patch
random-eliminate-redundant-new_rotate-variable.patch
random-remove-some-prefetch-logic.patch
random-simplify-add_ptr-logic.patch
random-make-mixing-interface-byte-oriented.patch
random-simplify-and-rename-credit_entropy_store.patch
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