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Steven Rostedt (Google) 62efb1e656 mm/rmap: fix misplaced parenthesis of a likely()
commit f67f8d4a8c upstream.

Running my yearly branch profiler to see where likely/unlikely annotation
may be added or removed, I discovered this:

correct incorrect  %        Function                  File              Line
 ------- ---------  -        --------                  ----              ----
       0   457918 100 page_try_dup_anon_rmap         rmap.h               264
[..]
  458021        0   0 page_try_dup_anon_rmap         rmap.h               265

I thought it was interesting that line 264 of rmap.h had a 100% incorrect
annotation, but the line directly below it was 100% correct. Looking at the
code:

	if (likely(!is_device_private_page(page) &&
	    unlikely(page_needs_cow_for_dma(vma, page))))

It didn't make sense. The "likely()" was around the entire if statement
(not just the "!is_device_private_page(page)"), which also included the
"unlikely()" portion of that if condition.

If the unlikely portion is unlikely to be true, that would make the entire
if condition unlikely to be true, so it made no sense at all to say the
entire if condition is true.

What is more likely to be likely is just the first part of the if statement
before the && operation. It's likely to be a misplaced parenthesis. And
after making the if condition broken into a likely() && unlikely(), both
now appear to be correct!

Link: https://lkml.kernel.org/r/20231201145936.5ddfdb50@gandalf.local.home
Fixes:fb3d824d1a46c ("mm/rmap: split page_dup_rmap() into page_dup_file_rmap() and page_try_dup_anon_rmap()")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-31 16:18:56 -08:00
arch rtc: Extend timeout for waiting for UIP to clear to 1s 2024-01-31 16:18:56 -08:00
block block: ensure we hold a queue reference when using queue limits 2024-01-25 15:35:57 -08:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto crypto: api - Disallow identical driver names 2024-01-31 16:18:49 -08:00
Documentation arm64: errata: Add Cortex-A510 speculative unprivileged load workaround 2024-01-31 16:18:55 -08:00
drivers nouveau/vmm: don't set addr on the fail path to avoid warning 2024-01-31 16:18:56 -08:00
fs ubifs: ubifs_symlink: Fix memleak of inode->i_link in error path 2024-01-31 16:18:56 -08:00
include mm/rmap: fix misplaced parenthesis of a likely() 2024-01-31 16:18:56 -08:00
init rootfs: Fix support for rootfstype= when root= is given 2024-01-25 15:35:46 -08:00
io_uring io_uring: adjust defer tw counting 2024-01-25 15:36:00 -08:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel kexec: do syscore_shutdown() in kernel_kexec 2024-01-31 16:18:56 -08:00
lib crypto: lib/mpi - Fix unexpected pointer access in mpi_ec_init 2024-01-31 16:18:49 -08:00
LICENSES
mm efi: disable mirror feature during crashkernel 2024-01-31 16:18:56 -08:00
net ipv6: mcast: fix data-race in ipv6_mc_down / mld_ifc_work 2024-01-25 15:36:00 -08:00
rust rust: Ignore preserve-most functions 2024-01-25 15:35:41 -08:00
samples vfio/mtty: Overhaul mtty interrupt handling 2024-01-10 17:16:55 +01:00
scripts scripts/get_abi: fix source path leak 2024-01-31 16:18:55 -08:00
security lsm: new security_file_ioctl_compat() hook 2024-01-31 16:18:54 -08:00
sound soundwire: fix initializing sysfs for same devices on different buses 2024-01-31 16:18:47 -08:00
tools selftests: mm: hugepage-vmemmap fails on 64K page size systems 2024-01-31 16:18:56 -08:00
usr
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap 20 hotfixes. 12 are cc:stable and the remainder address post-6.5 issues 2023-10-24 09:52:16 -10:00
.rustfmt.toml
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS Char/Misc driver fixes for 6.6-final 2023-10-28 07:51:27 -10:00
Makefile Linux 6.6.14 2024-01-25 15:36:01 -08:00
README

Linux kernel
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There are various text files in the Documentation/ subdirectory,
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Please read the Documentation/process/changes.rst file, as it contains the
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