From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754673AbcEPThn (ORCPT ); Mon, 16 May 2016 15:37:43 -0400 Received: from mail-yw0-f194.google.com ([209.85.161.194]:36627 "EHLO mail-yw0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754476AbcEPThk (ORCPT ); Mon, 16 May 2016 15:37:40 -0400 MIME-Version: 1.0 In-Reply-To: <1463417556-23087-3-git-send-email-pantelis.antoniou@konsulko.com> References: <1463417556-23087-1-git-send-email-pantelis.antoniou@konsulko.com> <1463417556-23087-3-git-send-email-pantelis.antoniou@konsulko.com> From: Rob Herring Date: Mon, 16 May 2016 14:37:20 -0500 Message-ID: Subject: Re: [PATCH v2 2/5] of: Support hashtable lookups for phandles To: Pantelis Antoniou Cc: Frank Rowand , Matt Porter , Grant Likely , Koen Kooi , Guenter Roeck , Marek Vasut , Geert Uytterhoeven , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Pantelis Antoniou Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 16, 2016 at 11:52 AM, Pantelis Antoniou wrote: > When a device tree contains a lot of phandles, resolving one > takes time because the original method uses a search against > all nodes (not just the ones with phandles). > > Signed-off-by: Pantelis Antoniou > --- > drivers/of/base.c | 41 ++++++++++++++++++++++++++++++++++++++--- > drivers/of/dynamic.c | 8 ++++++++ > drivers/of/of_private.h | 33 +++++++++++++++++++++++++++++++++ > include/linux/of.h | 2 ++ > 4 files changed, 81 insertions(+), 3 deletions(-) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index 20bbc2f..436a088 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -27,6 +27,7 @@ > #include > #include > #include > +#include > > #include "of_private.h" > > @@ -41,6 +42,18 @@ static const char *of_stdout_options; > > struct kset *of_kset; > > +const struct rhashtable_params of_phandle_ht_params = { static > + .key_offset = offsetof(struct device_node, phandle), /* base offset */ > + .key_len = sizeof(phandle), > + .head_offset = offsetof(struct device_node, ht_node), > + .automatic_shrinking = true, > +}; > + > +struct rhashtable *of_phandle_ht; > + > +/* default is false */ > +bool of_phandle_ht_is_disabled; I think this should go. The unittest alone is not enough reason to keep. > + > /* > * Used to protect the of_aliases, to hold off addition of nodes to sysfs. > * This mutex must be held whenever modifications are being made to the > @@ -162,6 +175,12 @@ int __of_attach_node_post(struct device_node *np) > struct property *pp; > int rc; > > + if (of_phandle_ht_available()) { This can never be false as this function should only get called after init. > + rc = of_phandle_ht_insert(np); > + WARN(rc, "insert to phandle hash fail @%s\n", > + of_node_full_name(np)); > + } > + > if (!IS_ENABLED(CONFIG_SYSFS)) > return 0; > > @@ -194,6 +213,17 @@ void __init of_core_init(void) > struct device_node *np; > int ret; > > + of_phandle_ht = kzalloc(sizeof(*of_phandle_ht), GFP_KERNEL); > + if (!of_phandle_ht) { > + pr_warn("devicetree: Failed to allocate hashtable\n"); > + return; > + } > + ret = rhashtable_init(of_phandle_ht, &of_phandle_ht_params); > + if (ret) { > + pr_warn("devicetree: Failed to initialize hashtable\n"); > + return; > + } > + > /* Create the kset, and register existing nodes */ > mutex_lock(&of_mutex); > of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj); > @@ -1073,9 +1103,14 @@ struct device_node *of_find_node_by_phandle(phandle handle) > return NULL; > > raw_spin_lock_irqsave(&devtree_lock, flags); > - for_each_of_allnodes(np) > - if (np->phandle == handle) > - break; > + /* when we're ready use the hash table (and not disabled) */ > + if (of_phandle_ht_available() && !of_phandle_ht_is_disabled) Just "if (of_phandle_ht)" > + np = of_phandle_ht_lookup(handle); > + else { /* fallback */ > + for_each_of_allnodes(np) > + if (np->phandle == handle) > + break; > + } > of_node_get(np); > raw_spin_unlock_irqrestore(&devtree_lock, flags); > return np; > diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c > index 34ca783..931b905 100644 > --- a/drivers/of/dynamic.c > +++ b/drivers/of/dynamic.c > @@ -11,6 +11,7 @@ > #include > #include > #include > +#include > > #include "of_private.h" > > @@ -44,6 +45,13 @@ EXPORT_SYMBOL(of_node_put); > void __of_detach_node_post(struct device_node *np) > { > struct property *pp; > + int rc; > + > + if (of_phandle_ht_available()) { Likewise, this can't be false either. > + rc = of_phandle_ht_remove(np); > + WARN(rc, "remove from phandle hash fail @%s\n", > + of_node_full_name(np)); > + } > > if (!IS_ENABLED(CONFIG_SYSFS)) > return; > diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h > index 10b0342..386ae71 100644 > --- a/drivers/of/of_private.h > +++ b/drivers/of/of_private.h > @@ -101,4 +101,37 @@ static inline int of_overlay_init(void) > } > #endif > > +extern const struct rhashtable_params of_phandle_ht_params; > +extern struct rhashtable *of_phandle_ht; > + > +/* for unittest use */ > +extern bool of_phandle_ht_is_disabled; > + > +static inline bool of_phandle_ht_available(void) > +{ > + return of_phandle_ht != NULL; > +} > + > +static inline int of_phandle_ht_insert(struct device_node *np) > +{ > + if (!np || !np->phandle) > + return 0; > + return rhashtable_insert_fast(of_phandle_ht, > + &np->ht_node, of_phandle_ht_params); > +} > + > +static inline int of_phandle_ht_remove(struct device_node *np) > +{ > + if (!np || !np->phandle) > + return 0; > + return rhashtable_remove_fast(of_phandle_ht, > + &np->ht_node, of_phandle_ht_params); > +} > + > +static inline struct device_node *of_phandle_ht_lookup(phandle handle) > +{ > + return rhashtable_lookup_fast(of_phandle_ht, > + &handle, of_phandle_ht_params); > +} > + > #endif /* _LINUX_OF_PRIVATE_H */ > diff --git a/include/linux/of.h b/include/linux/of.h > index 18a8e59..9de9a3f 100644 > --- a/include/linux/of.h > +++ b/include/linux/of.h > @@ -25,6 +25,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -52,6 +53,7 @@ struct device_node { > phandle phandle; > const char *full_name; > struct fwnode_handle fwnode; > + struct rhash_head ht_node; Place next to .phandle as both will be accessed at the same time. > > struct property *properties; > struct property *deadprops; /* removed properties */ > -- > 1.7.12 >