linux-kernel - [PATCH 1/2] staging: android: ashmem: Remove use of unlikely()

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Date:   Tue, 19 Jun 2018 17:57:34 -0700
From:   Alistair Strachan <astrachan@...gle.com>
To:     linux-kernel@...r.kernel.org
Cc:     Alistair Strachan <astrachan@...gle.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Arve Hjønnevåg" <arve@...roid.com>,
        Todd Kjos <tkjos@...roid.com>,
        Martijn Coenen <maco@...roid.com>, devel@...verdev.osuosl.org,
        kernel-team@...roid.com, Joel Fernandes <joel@...lfernandes.org>
Subject: [PATCH 1/2] staging: android: ashmem: Remove use of unlikely()

There is no speed difference, and it makes the code harder to read.

Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Arve Hjønnevåg <arve@...roid.com>
Cc: Todd Kjos <tkjos@...roid.com>
Cc: Martijn Coenen <maco@...roid.com>
Cc: devel@...verdev.osuosl.org
Cc: linux-kernel@...r.kernel.org
Cc: kernel-team@...roid.com
Cc: Joel Fernandes <joel@...lfernandes.org>
Suggested-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Alistair Strachan <astrachan@...gle.com>
---
 drivers/staging/android/ashmem.c | 34 ++++++++++++++++----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index a1a0025b59e0..c6386e4f5c9b 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -178,7 +178,7 @@ static int range_alloc(struct ashmem_area *asma,
 	struct ashmem_range *range;
 
 	range = kmem_cache_zalloc(ashmem_range_cachep, GFP_KERNEL);
-	if (unlikely(!range))
+	if (!range)
 		return -ENOMEM;
 
 	range->asma = asma;
@@ -246,11 +246,11 @@ static int ashmem_open(struct inode *inode, struct file *file)
 	int ret;
 
 	ret = generic_file_open(inode, file);
-	if (unlikely(ret))
+	if (ret)
 		return ret;
 
 	asma = kmem_cache_zalloc(ashmem_area_cachep, GFP_KERNEL);
-	if (unlikely(!asma))
+	if (!asma)
 		return -ENOMEM;
 
 	INIT_LIST_HEAD(&asma->unpinned_list);
@@ -361,14 +361,14 @@ static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
 	mutex_lock(&ashmem_mutex);
 
 	/* user needs to SET_SIZE before mapping */
-	if (unlikely(!asma->size)) {
+	if (!asma->size) {
 		ret = -EINVAL;
 		goto out;
 	}
 
 	/* requested protection bits must match our allowed protection mask */
-	if (unlikely((vma->vm_flags & ~calc_vm_prot_bits(asma->prot_mask, 0)) &
-		     calc_vm_prot_bits(PROT_MASK, 0))) {
+	if ((vma->vm_flags & ~calc_vm_prot_bits(asma->prot_mask, 0)) &
+	    calc_vm_prot_bits(PROT_MASK, 0)) {
 		ret = -EPERM;
 		goto out;
 	}
@@ -486,7 +486,7 @@ static int set_prot_mask(struct ashmem_area *asma, unsigned long prot)
 	mutex_lock(&ashmem_mutex);
 
 	/* the user can only remove, not add, protection bits */
-	if (unlikely((asma->prot_mask & prot) != prot)) {
+	if ((asma->prot_mask & prot) != prot) {
 		ret = -EINVAL;
 		goto out;
 	}
@@ -524,7 +524,7 @@ static int set_name(struct ashmem_area *asma, void __user *name)
 		local_name[ASHMEM_NAME_LEN - 1] = '\0';
 	mutex_lock(&ashmem_mutex);
 	/* cannot change an existing mapping's name */
-	if (unlikely(asma->file))
+	if (asma->file)
 		ret = -EINVAL;
 	else
 		strcpy(asma->name + ASHMEM_NAME_PREFIX_LEN, local_name);
@@ -563,7 +563,7 @@ static int get_name(struct ashmem_area *asma, void __user *name)
 	 * Now we are just copying from the stack variable to userland
 	 * No lock held
 	 */
-	if (unlikely(copy_to_user(name, local_name, len)))
+	if (copy_to_user(name, local_name, len))
 		ret = -EFAULT;
 	return ret;
 }
@@ -701,25 +701,25 @@ static int ashmem_pin_unpin(struct ashmem_area *asma, unsigned long cmd,
 	size_t pgstart, pgend;
 	int ret = -EINVAL;
 
-	if (unlikely(copy_from_user(&pin, p, sizeof(pin))))
+	if (copy_from_user(&pin, p, sizeof(pin)))
 		return -EFAULT;
 
 	mutex_lock(&ashmem_mutex);
 
-	if (unlikely(!asma->file))
+	if (!asma->file)
 		goto out_unlock;
 
 	/* per custom, you can pass zero for len to mean "everything onward" */
 	if (!pin.len)
 		pin.len = PAGE_ALIGN(asma->size) - pin.offset;
 
-	if (unlikely((pin.offset | pin.len) & ~PAGE_MASK))
+	if ((pin.offset | pin.len) & ~PAGE_MASK)
 		goto out_unlock;
 
-	if (unlikely(((__u32)-1) - pin.offset < pin.len))
+	if (((__u32)-1) - pin.offset < pin.len)
 		goto out_unlock;
 
-	if (unlikely(PAGE_ALIGN(asma->size) < pin.offset + pin.len))
+	if (PAGE_ALIGN(asma->size) < pin.offset + pin.len)
 		goto out_unlock;
 
 	pgstart = pin.offset / PAGE_SIZE;
@@ -856,7 +856,7 @@ static int __init ashmem_init(void)
 	ashmem_area_cachep = kmem_cache_create("ashmem_area_cache",
 					       sizeof(struct ashmem_area),
 					       0, 0, NULL);
-	if (unlikely(!ashmem_area_cachep)) {
+	if (!ashmem_area_cachep) {
 		pr_err("failed to create slab cache\n");
 		goto out;
 	}
@@ -864,13 +864,13 @@ static int __init ashmem_init(void)
 	ashmem_range_cachep = kmem_cache_create("ashmem_range_cache",
 						sizeof(struct ashmem_range),
 						0, 0, NULL);
-	if (unlikely(!ashmem_range_cachep)) {
+	if (!ashmem_range_cachep) {
 		pr_err("failed to create slab cache\n");
 		goto out_free1;
 	}
 
 	ret = misc_register(&ashmem_misc);
-	if (unlikely(ret)) {
+	if (ret) {
 		pr_err("failed to register misc device!\n");
 		goto out_free2;
 	}