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Date:   Thu, 17 Nov 2022 08:46:21 -0800
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Subject: Re: [PATCH v5 1/4] NFSD: refactoring courtesy_client_reaper to a
 generic low memory shrinker
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To:     Chuck Lever III <chuck.lever@oracle.com>
Cc:     "jlayton@kernel.org" <jlayton@kernel.org>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>
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On 11/17/22 6:45 AM, Chuck Lever III wrote:
>
>> On Nov 16, 2022, at 10:44 PM, Dai Ngo <dai.ngo@oracle.com> wrote:
>>
>> Refactoring courtesy_client_reaper to generic low memory
>> shrinker so it can be used for other purposes.
>>
>> Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
>> ---
>> fs/nfsd/nfs4state.c | 25 ++++++++++++++++---------
>> 1 file changed, 16 insertions(+), 9 deletions(-)
>>
>> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
>> index 836bd825ca4a..142481bc96de 100644
>> --- a/fs/nfsd/nfs4state.c
>> +++ b/fs/nfsd/nfs4state.c
>> @@ -4347,7 +4347,7 @@ nfsd4_init_slabs(void)
>> }
>>
>> static unsigned long
>> -nfsd_courtesy_client_count(struct shrinker *shrink, struct shrink_control *sc)
>> +nfsd_lowmem_shrinker_count(struct shrinker *shrink, struct shrink_control *sc)
>> {
>> 	int cnt;
>> 	struct nfsd_net *nn = container_of(shrink,
>> @@ -4360,7 +4360,7 @@ nfsd_courtesy_client_count(struct shrinker *shrink, struct shrink_control *sc)
>> }
>>
>> static unsigned long
>> -nfsd_courtesy_client_scan(struct shrinker *shrink, struct shrink_control *sc)
>> +nfsd_lowmem_shrinker_scan(struct shrinker *shrink, struct shrink_control *sc)
>> {
>> 	return SHRINK_STOP;
>> }
>> @@ -4387,8 +4387,8 @@ nfsd4_init_leases_net(struct nfsd_net *nn)
>> 	nn->nfs4_max_clients = max_t(int, max_clients, NFS4_CLIENTS_PER_GB);
>>
>> 	atomic_set(&nn->nfsd_courtesy_clients, 0);
>> -	nn->nfsd_client_shrinker.scan_objects = nfsd_courtesy_client_scan;
>> -	nn->nfsd_client_shrinker.count_objects = nfsd_courtesy_client_count;
>> +	nn->nfsd_client_shrinker.scan_objects = nfsd_lowmem_shrinker_scan;
>> +	nn->nfsd_client_shrinker.count_objects = nfsd_lowmem_shrinker_count;
>> 	nn->nfsd_client_shrinker.seeks = DEFAULT_SEEKS;
>> 	return register_shrinker(&nn->nfsd_client_shrinker, "nfsd-client");
>> }
>> @@ -6125,17 +6125,24 @@ laundromat_main(struct work_struct *laundry)
>> }
>>
>> static void
>> -courtesy_client_reaper(struct work_struct *reaper)
>> +courtesy_client_reaper(struct nfsd_net *nn)
>> {
>> 	struct list_head reaplist;
>> -	struct delayed_work *dwork = to_delayed_work(reaper);
>> -	struct nfsd_net *nn = container_of(dwork, struct nfsd_net,
>> -					nfsd_shrinker_work);
>>
>> 	nfs4_get_courtesy_client_reaplist(nn, &reaplist);
>> 	nfs4_process_client_reaplist(&reaplist);
>> }
>>
>> +static void
>> +nfsd4_lowmem_shrinker(struct work_struct *work)
> All shrinkers run due to low memory, so I think this name
> is a bit redundant. How about nfsd4_state_shrinker?

ok, it makes sense.

Thanks,
-Dai

>
>
>> +{
>> +	struct delayed_work *dwork = to_delayed_work(work);
>> +	struct nfsd_net *nn = container_of(dwork, struct nfsd_net,
>> +				nfsd_shrinker_work);
>> +
>> +	courtesy_client_reaper(nn);
>> +}
>> +
>> static inline __be32 nfs4_check_fh(struct svc_fh *fhp, struct nfs4_stid *stp)
>> {
>> 	if (!fh_match(&fhp->fh_handle, &stp->sc_file->fi_fhandle))
>> @@ -7958,7 +7965,7 @@ static int nfs4_state_create_net(struct net *net)
>> 	INIT_LIST_HEAD(&nn->blocked_locks_lru);
>>
>> 	INIT_DELAYED_WORK(&nn->laundromat_work, laundromat_main);
>> -	INIT_DELAYED_WORK(&nn->nfsd_shrinker_work, courtesy_client_reaper);
>> +	INIT_DELAYED_WORK(&nn->nfsd_shrinker_work, nfsd4_lowmem_shrinker);
>> 	get_net(net);
>>
>> 	return 0;
>> -- 
>> 2.9.5
>>
> --
> Chuck Lever
>
>
>