Re: [PATCH 3/3] proc: use kzalloc instead of kmalloc and memset
2012/9/4 Ryan Mallon > > On 04/09/12 00:14, yan wrote: > > Signed-off-by: yan > > --- > > fs/proc/generic.c |3 +-- > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/fs/proc/generic.c b/fs/proc/generic.c > > index 9e8f631..38de015 100644 > > --- a/fs/proc/generic.c > > +++ b/fs/proc/generic.c > > @@ -616,10 +616,9 @@ static struct proc_dir_entry *__proc_create(struct > > proc_dir_entry **parent, > > > > len = strlen(fn); > > > > - ent = kmalloc(sizeof(struct proc_dir_entry) + len + 1, > > GFP_KERNEL); > > + ent = kzalloc(sizeof(struct proc_dir_entry) + len + 1, > > GFP_KERNEL); > > if (!ent) goto out; > > > > - memset(ent, 0, sizeof(struct proc_dir_entry)); > > memcpy(ent->name, fn, len + 1); > > ent->namelen = len; > > ent->mode = mode; > > Note that this change results in slightly different behaviour. Before > your change only sizeof(struct proc_dir_entry) is zero'ed by memset, and > then the name is filled in (the len + 1 part). After your change the > structure and the name field are both zeroed, so the name field is being > written to twice. The cost is probably negligible though. Oh, I didn't notice that actually. Thank you. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] proc: use kzalloc instead of kmalloc and memset
2012/9/4 Ryan Mallon rmal...@gmail.com On 04/09/12 00:14, yan wrote: Signed-off-by: yan clouds@gmail.com --- fs/proc/generic.c |3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 9e8f631..38de015 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -616,10 +616,9 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent, len = strlen(fn); - ent = kmalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL); + ent = kzalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL); if (!ent) goto out; - memset(ent, 0, sizeof(struct proc_dir_entry)); memcpy(ent-name, fn, len + 1); ent-namelen = len; ent-mode = mode; Note that this change results in slightly different behaviour. Before your change only sizeof(struct proc_dir_entry) is zero'ed by memset, and then the name is filled in (the len + 1 part). After your change the structure and the name field are both zeroed, so the name field is being written to twice. The cost is probably negligible though. Oh, I didn't notice that actually. Thank you. -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] proc: use kzalloc instead of kmalloc and memset
On 04/09/12 00:14, yan wrote: > Signed-off-by: yan > --- > fs/proc/generic.c |3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/fs/proc/generic.c b/fs/proc/generic.c > index 9e8f631..38de015 100644 > --- a/fs/proc/generic.c > +++ b/fs/proc/generic.c > @@ -616,10 +616,9 @@ static struct proc_dir_entry *__proc_create(struct > proc_dir_entry **parent, > > len = strlen(fn); > > - ent = kmalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL); > + ent = kzalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL); > if (!ent) goto out; > > - memset(ent, 0, sizeof(struct proc_dir_entry)); > memcpy(ent->name, fn, len + 1); > ent->namelen = len; > ent->mode = mode; Note that this change results in slightly different behaviour. Before your change only sizeof(struct proc_dir_entry) is zero'ed by memset, and then the name is filled in (the len + 1 part). After your change the structure and the name field are both zeroed, so the name field is being written to twice. The cost is probably negligible though. ~Ryan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 3/3] proc: use kzalloc instead of kmalloc and memset
Signed-off-by: yan --- fs/proc/generic.c |3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 9e8f631..38de015 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -616,10 +616,9 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent, len = strlen(fn); - ent = kmalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL); + ent = kzalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL); if (!ent) goto out; - memset(ent, 0, sizeof(struct proc_dir_entry)); memcpy(ent->name, fn, len + 1); ent->namelen = len; ent->mode = mode; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 3/3] proc: use kzalloc instead of kmalloc and memset
Signed-off-by: yan clouds@gmail.com --- fs/proc/generic.c |3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 9e8f631..38de015 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -616,10 +616,9 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent, len = strlen(fn); - ent = kmalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL); + ent = kzalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL); if (!ent) goto out; - memset(ent, 0, sizeof(struct proc_dir_entry)); memcpy(ent-name, fn, len + 1); ent-namelen = len; ent-mode = mode; -- 1.7.9.5 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] proc: use kzalloc instead of kmalloc and memset
On 04/09/12 00:14, yan wrote: Signed-off-by: yan clouds@gmail.com --- fs/proc/generic.c |3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 9e8f631..38de015 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -616,10 +616,9 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent, len = strlen(fn); - ent = kmalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL); + ent = kzalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL); if (!ent) goto out; - memset(ent, 0, sizeof(struct proc_dir_entry)); memcpy(ent-name, fn, len + 1); ent-namelen = len; ent-mode = mode; Note that this change results in slightly different behaviour. Before your change only sizeof(struct proc_dir_entry) is zero'ed by memset, and then the name is filled in (the len + 1 part). After your change the structure and the name field are both zeroed, so the name field is being written to twice. The cost is probably negligible though. ~Ryan -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
