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authorJoel Fernandes <joelagnelf@nvidia.com>2026-07-18 13:15:36 -0400
committerPaul E. McKenney <paulmck@kernel.org>2026-07-23 10:39:57 -0700
commit34ff636f322c6d5e4f0a52338fa63a7dff09a495 (patch)
tree7629759c1ec7148b95bc8ab3080df20a5ecd2273 /arch/alpha/lib/memchr.S
downloadlinux-stable-34ff636f322c6d5e4f0a52338fa63a7dff09a495.tar.gz
linux-stable-34ff636f322c6d5e4f0a52338fa63a7dff09a495.zip
scftorture: Count single_rpc offline failures in statistics outputgrafted
scf_torture_stats_print() aggregates each invoker thread's counters into a local scf_statistics structure before printing, but the n_single_rpc_ofl field is missing from the aggregation loop. As a result, the "single_rpc_ofl" value printed in the statistics line is always zero, even when smp_call_function_single() invocations for the RPC test have failed due to offline CPUs and been counted by the invoker threads. Add the missing accumulation so that the printed value reflects the actual counts. Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'arch/alpha/lib/memchr.S')
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1 files changed, 165 insertions, 0 deletions
diff --git a/arch/alpha/lib/memchr.S b/arch/alpha/lib/memchr.S
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+/* Copyright (C) 1996 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by David Mosberger (davidm@cs.arizona.edu).
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+/* Finds characters in a memory area. Optimized for the Alpha:
+
+ - memory accessed as aligned quadwords only
+ - uses cmpbge to compare 8 bytes in parallel
+ - does binary search to find 0 byte in last
+ quadword (HAKMEM needed 12 instructions to
+ do this instead of the 9 instructions that
+ binary search needs).
+
+For correctness consider that:
+
+ - only minimum number of quadwords may be accessed
+ - the third argument is an unsigned long
+*/
+#include <linux/export.h>
+ .set noreorder
+ .set noat
+
+ .globl memchr
+ .ent memchr
+memchr:
+ .frame $30,0,$26,0
+ .prologue 0
+
+ # Hack -- if someone passes in (size_t)-1, hoping to just
+ # search til the end of the address space, we will overflow
+ # below when we find the address of the last byte. Given
+ # that we will never have a 56-bit address space, cropping
+ # the length is the easiest way to avoid trouble.
+ zap $18, 0x80, $5 #-e0 :
+
+ beq $18, $not_found # .. e1 :
+ ldq_u $1, 0($16) # e1 : load first quadword
+ insbl $17, 1, $2 # .. e0 : $2 = 000000000000ch00
+ and $17, 0xff, $17 #-e0 : $17 = 00000000000000ch
+ cmpult $18, 9, $4 # .. e1 :
+ or $2, $17, $17 # e0 : $17 = 000000000000chch
+ lda $3, -1($31) # .. e1 :
+ sll $17, 16, $2 #-e0 : $2 = 00000000chch0000
+ addq $16, $5, $5 # .. e1 :
+ or $2, $17, $17 # e1 : $17 = 00000000chchchch
+ unop # :
+ sll $17, 32, $2 #-e0 : $2 = chchchch00000000
+ or $2, $17, $17 # e1 : $17 = chchchchchchchch
+ extql $1, $16, $7 # e0 :
+ beq $4, $first_quad # .. e1 :
+
+ ldq_u $6, -1($5) #-e1 : eight or less bytes to search
+ extqh $6, $16, $6 # .. e0 :
+ mov $16, $0 # e0 :
+ or $7, $6, $1 # .. e1 : $1 = quadword starting at $16
+
+ # Deal with the case where at most 8 bytes remain to be searched
+ # in $1. E.g.:
+ # $18 = 6
+ # $1 = ????c6c5c4c3c2c1
+$last_quad:
+ negq $18, $6 #-e0 :
+ xor $17, $1, $1 # .. e1 :
+ srl $3, $6, $6 # e0 : $6 = mask of $18 bits set
+ cmpbge $31, $1, $2 # .. e1 :
+ and $2, $6, $2 #-e0 :
+ beq $2, $not_found # .. e1 :
+
+$found_it:
+ # Now, determine which byte matched:
+ negq $2, $3 # e0 :
+ and $2, $3, $2 # e1 :
+
+ and $2, 0x0f, $1 #-e0 :
+ addq $0, 4, $3 # .. e1 :
+ cmoveq $1, $3, $0 # e0 :
+
+ addq $0, 2, $3 # .. e1 :
+ and $2, 0x33, $1 #-e0 :
+ cmoveq $1, $3, $0 # .. e1 :
+
+ and $2, 0x55, $1 # e0 :
+ addq $0, 1, $3 # .. e1 :
+ cmoveq $1, $3, $0 #-e0 :
+
+$done: ret # .. e1 :
+
+ # Deal with the case where $18 > 8 bytes remain to be
+ # searched. $16 may not be aligned.
+ .align 4
+$first_quad:
+ andnot $16, 0x7, $0 #-e1 :
+ insqh $3, $16, $2 # .. e0 : $2 = 0000ffffffffffff ($16<0:2> ff)
+ xor $1, $17, $1 # e0 :
+ or $1, $2, $1 # e1 : $1 = ====ffffffffffff
+ cmpbge $31, $1, $2 #-e0 :
+ bne $2, $found_it # .. e1 :
+
+ # At least one byte left to process.
+
+ ldq $1, 8($0) # e0 :
+ subq $5, 1, $18 # .. e1 :
+ addq $0, 8, $0 #-e0 :
+
+ # Make $18 point to last quad to be accessed (the
+ # last quad may or may not be partial).
+
+ andnot $18, 0x7, $18 # .. e1 :
+ cmpult $0, $18, $2 # e0 :
+ beq $2, $final # .. e1 :
+
+ # At least two quads remain to be accessed.
+
+ subq $18, $0, $4 #-e0 : $4 <- nr quads to be processed
+ and $4, 8, $4 # e1 : odd number of quads?
+ bne $4, $odd_quad_count # e1 :
+
+ # At least three quads remain to be accessed
+
+ mov $1, $4 # e0 : move prefetched value to correct reg
+
+ .align 4
+$unrolled_loop:
+ ldq $1, 8($0) #-e0 : prefetch $1
+ xor $17, $4, $2 # .. e1 :
+ cmpbge $31, $2, $2 # e0 :
+ bne $2, $found_it # .. e1 :
+
+ addq $0, 8, $0 #-e0 :
+$odd_quad_count:
+ xor $17, $1, $2 # .. e1 :
+ ldq $4, 8($0) # e0 : prefetch $4
+ cmpbge $31, $2, $2 # .. e1 :
+ addq $0, 8, $6 #-e0 :
+ bne $2, $found_it # .. e1 :
+
+ cmpult $6, $18, $6 # e0 :
+ addq $0, 8, $0 # .. e1 :
+ bne $6, $unrolled_loop #-e1 :
+
+ mov $4, $1 # e0 : move prefetched value into $1
+$final: subq $5, $0, $18 # .. e1 : $18 <- number of bytes left to do
+ bne $18, $last_quad # e1 :
+
+$not_found:
+ mov $31, $0 #-e0 :
+ ret # .. e1 :
+
+ .end memchr
+ EXPORT_SYMBOL(memchr)