The patch titled
Subject: checkpatch: check for nested (un)?likely() calls
has been added to the -mm tree. Its filename is
checkpatch-check-for-nested-unlikely-calls.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/checkpatch-check-for-nested-unlikely-calls.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/checkpatch-check-for-nested-unlikely-calls.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Denis Efremov <efremov@xxxxxxxxx>
Subject: checkpatch: check for nested (un)?likely() calls
IS_ERR(), IS_ERR_OR_NULL(), IS_ERR_VALUE() and WARN*() already contain
unlikely() optimization internally. Thus, there is no point in calling
these functions and defines under likely()/unlikely().
This check is based on the coccinelle rule developed by Enrico Weigelt
https://lore.kernel.org/lkml/1559767582-11081-1-git-send-email-info@xxxxxxxxx/
Link: http://lkml.kernel.org/r/20190829165025.15750-1-efremov@xxxxxxxxx
Signed-off-by: Denis Efremov <efremov@xxxxxxxxx>
Cc: Joe Perches <joe@xxxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Anton Altaparmakov <anton@xxxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Boris Pismenny <borisp@xxxxxxxxxxxx>
Cc: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Denis Efremov <efremov@xxxxxxxxx>
Cc: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@xxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Leon Romanovsky <leon@xxxxxxxxxx>
Cc: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Cc: Rob Clark <robdclark@xxxxxxxxx>
Cc: Saeed Mahameed <saeedm@xxxxxxxxxxxx>
Cc: Sean Paul <sean@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
scripts/checkpatch.pl | 6 ++++++
1 file changed, 6 insertions(+)
--- a/scripts/checkpatch.pl~checkpatch-check-for-nested-unlikely-calls
+++ a/scripts/checkpatch.pl
@@ -6529,6 +6529,12 @@ sub process {
"Using $1 should generally have parentheses around the comparison\n" . $herecurr);
}
+# nested likely/unlikely calls
+ if ($line =~ /\b(?:(?:un)?likely)\s*\(\s*!?\s*(IS_ERR(?:_OR_NULL|_VALUE)?|WARN)/) {
+ WARN("LIKELY_MISUSE",
+ "nested (un)?likely() calls, $1 already uses unlikely() internally\n" . $herecurr);
+ }
+
# whine mightly about in_atomic
if ($line =~ /\bin_atomic\s*\(/) {
if ($realfile =~ m@^drivers/@) {
_
Patches currently in -mm which might be from efremov@xxxxxxxxx are
checkpatch-check-for-nested-unlikely-calls.patch
drm-msm-remove-unlikely-from-warn_on-conditions.patch
net-mlx5e-remove-unlikely-from-warn-condition.patch
xen-events-remove-unlikely-from-warn-condition.patch
fs-remove-unlikely-from-warn_on-condition.patch
wimax-i2400m-remove-unlikely-from-warn-condition.patch
xfs-remove-unlikely-from-warn_on-condition.patch
ib-hfi1-remove-unlikely-from-is_err-condition.patch
udp-remove-unlikely-from-is_err-condition.patch
ntfs-remove-unlikely-from-is_err-conditions.patch
