2013-10-14 06:02:01

by Benny Halevy

[permalink] [raw]
Subject: [PATCH] nfsd: no need to unhash_stid before free

idr_remove is about to be called before kmem_cache_free so unhashing it
is redundant

Signed-off-by: Benny Halevy <[email protected]>
---
fs/nfsd/nfs4state.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 0874998..06984e3 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -668,7 +668,6 @@ static void unhash_open_stateid(struct nfs4_ol_stateid *stp)
static void release_open_stateid(struct nfs4_ol_stateid *stp)
{
unhash_open_stateid(stp);
- unhash_stid(&stp->st_stid);
free_generic_stateid(stp);
}

@@ -690,7 +689,6 @@ static void release_last_closed_stateid(struct nfs4_openowner *oo)
struct nfs4_ol_stateid *s = oo->oo_last_closed_stid;

if (s) {
- unhash_stid(&s->st_stid);
free_generic_stateid(s);
oo->oo_last_closed_stid = NULL;
}
@@ -3998,10 +3996,9 @@ static void nfsd4_close_open_stateid(struct nfs4_ol_stateid *s)

nfsd4_close_open_stateid(stp);

- if (cstate->minorversion) {
- unhash_stid(&stp->st_stid);
+ if (cstate->minorversion)
free_generic_stateid(stp);
- } else
+ else
oo->oo_last_closed_stid = stp;

if (list_empty(&oo->oo_owner.so_stateids)) {
--
1.8.3.1



2013-10-28 18:32:16

by J. Bruce Fields

[permalink] [raw]
Subject: Re: [PATCH] nfsd: no need to unhash_stid before free

On Mon, Oct 14, 2013 at 09:01:55AM +0300, Benny Halevy wrote:
> idr_remove is about to be called before kmem_cache_free so unhashing it
> is redundant

This leaves only two unhash_stid callers, in release_lock_stateid and
unhash_stid, both called just before destroying the stateid, so perhaps
we should remove those and unhash_stid?

--b.

>
> Signed-off-by: Benny Halevy <[email protected]>
> ---
> fs/nfsd/nfs4state.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 0874998..06984e3 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -668,7 +668,6 @@ static void unhash_open_stateid(struct nfs4_ol_stateid *stp)
> static void release_open_stateid(struct nfs4_ol_stateid *stp)
> {
> unhash_open_stateid(stp);
> - unhash_stid(&stp->st_stid);
> free_generic_stateid(stp);
> }
>
> @@ -690,7 +689,6 @@ static void release_last_closed_stateid(struct nfs4_openowner *oo)
> struct nfs4_ol_stateid *s = oo->oo_last_closed_stid;
>
> if (s) {
> - unhash_stid(&s->st_stid);
> free_generic_stateid(s);
> oo->oo_last_closed_stid = NULL;
> }
> @@ -3998,10 +3996,9 @@ static void nfsd4_close_open_stateid(struct nfs4_ol_stateid *s)
>
> nfsd4_close_open_stateid(stp);
>
> - if (cstate->minorversion) {
> - unhash_stid(&stp->st_stid);
> + if (cstate->minorversion)
> free_generic_stateid(stp);
> - } else
> + else
> oo->oo_last_closed_stid = stp;
>
> if (list_empty(&oo->oo_owner.so_stateids)) {
> --
> 1.8.3.1
>

2013-10-29 07:00:19

by Benny Halevy

[permalink] [raw]
Subject: Re: [PATCH] nfsd: no need to unhash_stid before free

On 2013-10-28 20:32, J. Bruce Fields wrote:
> On Mon, Oct 14, 2013 at 09:01:55AM +0300, Benny Halevy wrote:
>> idr_remove is about to be called before kmem_cache_free so unhashing it
>> is redundant
>
> This leaves only two unhash_stid callers, in release_lock_stateid and
> unhash_stid, both called just before destroying the stateid, so perhaps
> we should remove those and unhash_stid?

In my state lock elimination patchset I actually keep using unhash_stid
after refactoring non-blocking unhashing from the blocking release
so I don't think it's worth it to remove the call.
That said, we can still open code it but encapsulating the assignment
in unhash_stid() which the compiler can inline anyway seems cleaner to me.

Benny

>
> --b.
>
>>
>> Signed-off-by: Benny Halevy <[email protected]>
>> ---
>> fs/nfsd/nfs4state.c | 7 ++-----
>> 1 file changed, 2 insertions(+), 5 deletions(-)
>>
>> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
>> index 0874998..06984e3 100644
>> --- a/fs/nfsd/nfs4state.c
>> +++ b/fs/nfsd/nfs4state.c
>> @@ -668,7 +668,6 @@ static void unhash_open_stateid(struct nfs4_ol_stateid *stp)
>> static void release_open_stateid(struct nfs4_ol_stateid *stp)
>> {
>> unhash_open_stateid(stp);
>> - unhash_stid(&stp->st_stid);
>> free_generic_stateid(stp);
>> }
>>
>> @@ -690,7 +689,6 @@ static void release_last_closed_stateid(struct nfs4_openowner *oo)
>> struct nfs4_ol_stateid *s = oo->oo_last_closed_stid;
>>
>> if (s) {
>> - unhash_stid(&s->st_stid);
>> free_generic_stateid(s);
>> oo->oo_last_closed_stid = NULL;
>> }
>> @@ -3998,10 +3996,9 @@ static void nfsd4_close_open_stateid(struct nfs4_ol_stateid *s)
>>
>> nfsd4_close_open_stateid(stp);
>>
>> - if (cstate->minorversion) {
>> - unhash_stid(&stp->st_stid);
>> + if (cstate->minorversion)
>> free_generic_stateid(stp);
>> - } else
>> + else
>> oo->oo_last_closed_stid = stp;
>>
>> if (list_empty(&oo->oo_owner.so_stateids)) {
>> --
>> 1.8.3.1
>>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>

2013-10-29 13:39:52

by J. Bruce Fields

[permalink] [raw]
Subject: Re: [PATCH] nfsd: no need to unhash_stid before free

On Tue, Oct 29, 2013 at 09:00:15AM +0200, Benny Halevy wrote:
> On 2013-10-28 20:32, J. Bruce Fields wrote:
> > On Mon, Oct 14, 2013 at 09:01:55AM +0300, Benny Halevy wrote:
> >> idr_remove is about to be called before kmem_cache_free so unhashing it
> >> is redundant
> >
> > This leaves only two unhash_stid callers, in release_lock_stateid and
> > unhash_stid, both called just before destroying the stateid, so perhaps
> > we should remove those and unhash_stid?
>
> In my state lock elimination patchset I actually keep using unhash_stid
> after refactoring non-blocking unhashing from the blocking release
> so I don't think it's worth it to remove the call.
> That said, we can still open code it but encapsulating the assignment
> in unhash_stid() which the compiler can inline anyway seems cleaner to me.

OK, sure, sounds fine.

--b.

>
> Benny
>
> >
> > --b.
> >
> >>
> >> Signed-off-by: Benny Halevy <[email protected]>
> >> ---
> >> fs/nfsd/nfs4state.c | 7 ++-----
> >> 1 file changed, 2 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> >> index 0874998..06984e3 100644
> >> --- a/fs/nfsd/nfs4state.c
> >> +++ b/fs/nfsd/nfs4state.c
> >> @@ -668,7 +668,6 @@ static void unhash_open_stateid(struct nfs4_ol_stateid *stp)
> >> static void release_open_stateid(struct nfs4_ol_stateid *stp)
> >> {
> >> unhash_open_stateid(stp);
> >> - unhash_stid(&stp->st_stid);
> >> free_generic_stateid(stp);
> >> }
> >>
> >> @@ -690,7 +689,6 @@ static void release_last_closed_stateid(struct nfs4_openowner *oo)
> >> struct nfs4_ol_stateid *s = oo->oo_last_closed_stid;
> >>
> >> if (s) {
> >> - unhash_stid(&s->st_stid);
> >> free_generic_stateid(s);
> >> oo->oo_last_closed_stid = NULL;
> >> }
> >> @@ -3998,10 +3996,9 @@ static void nfsd4_close_open_stateid(struct nfs4_ol_stateid *s)
> >>
> >> nfsd4_close_open_stateid(stp);
> >>
> >> - if (cstate->minorversion) {
> >> - unhash_stid(&stp->st_stid);
> >> + if (cstate->minorversion)
> >> free_generic_stateid(stp);
> >> - } else
> >> + else
> >> oo->oo_last_closed_stid = stp;
> >>
> >> if (list_empty(&oo->oo_owner.so_stateids)) {
> >> --
> >> 1.8.3.1
> >>
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
> > the body of a message to [email protected]
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> >
> --
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