Return-Path: Received: from natasha.panasas.com ([67.152.220.90]:40938 "EHLO natasha.panasas.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750978Ab1HJSMt (ORCPT ); Wed, 10 Aug 2011 14:12:49 -0400 Message-ID: <4E42CA15.3020103@panasas.com> Date: Wed, 10 Aug 2011 11:12:37 -0700 From: Boaz Harrosh To: Peng Tao CC: Benny Halevy , , Peng Tao Subject: Re: [PATCH 3/5] pnfs: introduce pnfs private workqueue References: <1312685635-1593-1-git-send-email-bergwolf@gmail.com> <1312685635-1593-3-git-send-email-bergwolf@gmail.com> In-Reply-To: <1312685635-1593-3-git-send-email-bergwolf@gmail.com> Content-Type: text/plain; charset="UTF-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On 08/06/2011 07:53 PM, Peng Tao wrote: > For layoutdriver io done functions, default workqueue is not a good place > as the code is executed in IO path. So add a pnfs private workqueue to handle > them. > > Also change block and object layout code to make use of this private workqueue. > > Signed-off-by: Peng Tao > --- > fs/nfs/blocklayout/blocklayout.c | 17 ++++++++++---- > fs/nfs/objlayout/objio_osd.c | 8 ++++++ > fs/nfs/objlayout/objlayout.c | 4 +- > fs/nfs/pnfs.c | 46 +++++++++++++++++++++++++++++++++++++- > fs/nfs/pnfs.h | 4 +++ > 5 files changed, 71 insertions(+), 8 deletions(-) > > diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c > index 9561c8f..3aef9f0 100644 > --- a/fs/nfs/blocklayout/blocklayout.c > +++ b/fs/nfs/blocklayout/blocklayout.c > @@ -228,7 +228,7 @@ bl_end_par_io_read(void *data) > struct nfs_read_data *rdata = data; > > INIT_WORK(&rdata->task.u.tk_work, bl_read_cleanup); > - schedule_work(&rdata->task.u.tk_work); > + queue_work(pnfsiod_workqueue, &rdata->task.u.tk_work); If pnfsiod_workqueue is a global pnfs resource that users should only use with global pnfsiod_start/stop() then I would like a wrapper around queue_work, pnfsiod_queue_work(tk_work) that keeps the pnfsiod_workqueue private to that subsystem. (And the proper checks could be made, and races avoided) > } > > /* We don't want normal .rpc_call_done callback used, so we replace it > @@ -418,7 +418,7 @@ static void bl_end_par_io_write(void *data) > wdata->task.tk_status = 0; > wdata->verf.committed = NFS_FILE_SYNC; > INIT_WORK(&wdata->task.u.tk_work, bl_write_cleanup); > - schedule_work(&wdata->task.u.tk_work); > + queue_work(pnfsiod_workqueue, &wdata->task.u.tk_work); > } > > /* FIXME STUB - mark intersection of layout and page as bad, so is not > @@ -977,29 +977,35 @@ static int __init nfs4blocklayout_init(void) > if (ret) > goto out; > > + ret = pnfsiod_start(); > + if (ret) > + goto out_remove; > + > init_waitqueue_head(&bl_wq); > > mnt = rpc_get_mount(); > if (IS_ERR(mnt)) { > ret = PTR_ERR(mnt); > - goto out_remove; > + goto out_stop; > } > > ret = vfs_path_lookup(mnt->mnt_root, > mnt, > NFS_PIPE_DIRNAME, 0, &path); > if (ret) > - goto out_remove; > + goto out_stop; > > bl_device_pipe = rpc_mkpipe(path.dentry, "blocklayout", NULL, > &bl_upcall_ops, 0); > if (IS_ERR(bl_device_pipe)) { > ret = PTR_ERR(bl_device_pipe); > - goto out_remove; > + goto out_stop; > } > out: > return ret; > > +out_stop: > + pnfsiod_stop(); > out_remove: > pnfs_unregister_layoutdriver(&blocklayout_type); > return ret; > @@ -1011,6 +1017,7 @@ static void __exit nfs4blocklayout_exit(void) > __func__); > > pnfs_unregister_layoutdriver(&blocklayout_type); > + pnfsiod_stop(); > rpc_unlink(bl_device_pipe); > } > > diff --git a/fs/nfs/objlayout/objio_osd.c b/fs/nfs/objlayout/objio_osd.c > index d0cda12..f28013f 100644 > --- a/fs/nfs/objlayout/objio_osd.c > +++ b/fs/nfs/objlayout/objio_osd.c > @@ -1042,7 +1042,14 @@ static int __init > objlayout_init(void) > { > int ret = pnfs_register_layoutdriver(&objlayout_type); > + if (ret) > + goto out; > > + ret = pnfsiod_start(); > + if (ret) > + pnfs_unregister_layoutdriver(&objlayout_type); > + > +out: > if (ret) > printk(KERN_INFO > "%s: Registering OSD pNFS Layout Driver failed: error=%d\n", > @@ -1057,6 +1064,7 @@ static void __exit > objlayout_exit(void) > { > pnfs_unregister_layoutdriver(&objlayout_type); > + pnfsiod_stop(); > printk(KERN_INFO "%s: Unregistered OSD pNFS Layout Driver\n", > __func__); > } > diff --git a/fs/nfs/objlayout/objlayout.c b/fs/nfs/objlayout/objlayout.c > index 1d06f8e..1e7fa05 100644 > --- a/fs/nfs/objlayout/objlayout.c > +++ b/fs/nfs/objlayout/objlayout.c > @@ -305,7 +305,7 @@ objlayout_read_done(struct objlayout_io_state *state, ssize_t status, bool sync) > pnfs_ld_read_done(rdata); > else { > INIT_WORK(&rdata->task.u.tk_work, _rpc_read_complete); > - schedule_work(&rdata->task.u.tk_work); > + queue_task(pnfsiod_workqueue, &rdata->task.u.tk_work); > } > } > > @@ -396,7 +396,7 @@ objlayout_write_done(struct objlayout_io_state *state, ssize_t status, > pnfs_ld_write_done(wdata); > else { > INIT_WORK(&wdata->task.u.tk_work, _rpc_write_complete); > - schedule_work(&wdata->task.u.tk_work); > + queue_task(pnfsiod_workqueue, &wdata->task.u.tk_work); > } > } > > diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c > index 66fc854..e183a4f 100644 > --- a/fs/nfs/pnfs.c > +++ b/fs/nfs/pnfs.c > @@ -38,7 +38,7 @@ > /* Locking: > * > * pnfs_spinlock: > - * protects pnfs_modules_tbl. > + * protects pnfs_modules_tbl, pnfsiod_workqueue and pnfsiod_users. > */ > static DEFINE_SPINLOCK(pnfs_spinlock); > > @@ -47,6 +47,9 @@ static DEFINE_SPINLOCK(pnfs_spinlock); > */ > static LIST_HEAD(pnfs_modules_tbl); > > +struct workqueue_struct *pnfsiod_workqueue; > +static int pnfsiod_users = 0; > + > /* Return the registered pnfs layout driver module matching given id */ > static struct pnfs_layoutdriver_type * > find_pnfs_driver_locked(u32 id) > @@ -1517,3 +1520,44 @@ out: > dprintk("<-- %s status %d\n", __func__, status); > return status; > } > + > +/* > + * start up the pnfsiod workqueue > + */ > +int pnfsiod_start(void) > +{ > + struct workqueue_struct *wq; > + dprintk("RPC: creating workqueue pnfsiod\n"); > + wq = alloc_workqueue("pnfsiod", WQ_MEM_RECLAIM, 0); > + if (wq == NULL) > + return -ENOMEM; > + spin_lock(&pnfs_spinlock); > + pnfsiod_users++; > + if (pnfsiod_workqueue == NULL) { > + pnfsiod_workqueue = wq; > + } else { > + destroy_workqueue(wq); > + } > + spin_unlock(&pnfs_spinlock); > + return 0; > +} What? why not a simple: + int ret = 0; + spin_lock(&pnfs_spinlock); + if (pnfsiod_workqueue == NULL) { + pnfsiod_workqueue = alloc_workqueue("pnfsiod", WQ_MEM_RECLAIM, 0); + if (unlikely!(pnfsiod_workqueue)) { + ret = -ENOMEM; goto out; } + } + pnfsiod_users++; + out: + spin_unlock(&pnfs_spinlock); + return ret; > +EXPORT_SYMBOL_GPL(pnfsiod_start); > + > +/* > + * Destroy the pnfsiod workqueue > + */ > +void pnfsiod_stop(void) > +{ > + struct workqueue_struct *wq == NULL; > + > + spin_lock(&pnfs_spinlock); > + pnfsiod_users--; > + if (pnfsiod_users == 0) { > + wq = pnfsiod_workqueue; > + pnfsiod_workqueue = NULL; > + } > + spin_unlock(&pnfs_spinlock); > + if (wq) > + destroy_workqueue(wq); Does destroy_workqueue wait for all pending work? > +} > +EXPORT_SYMBOL_GPL(pnfsiod_stop); > diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h > index 01cbfd5..af7530b 100644 > --- a/fs/nfs/pnfs.h > +++ b/fs/nfs/pnfs.h > @@ -155,6 +155,10 @@ struct pnfs_devicelist { > extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *); > extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *); > > +extern struct workqueue_struct *pnfsiod_workqueue; As I said: +extern int pnfsiod_queue_work(...); > +extern int pnfsiod_start(void); > +extern void pnfsiod_stop(void); > + > /* nfs4proc.c */ > extern int nfs4_proc_getdevicelist(struct nfs_server *server, > const struct nfs_fh *fh, Thanks for doing this, looks good other wise Boaz