Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752485AbdCER0M (ORCPT ); Sun, 5 Mar 2017 12:26:12 -0500 Received: from mail3-relais-sop.national.inria.fr ([192.134.164.104]:3418 "EHLO mail3-relais-sop.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751905AbdCER0L (ORCPT ); Sun, 5 Mar 2017 12:26:11 -0500 X-IronPort-AV: E=Sophos;i="5.35,249,1484002800"; d="scan'208";a="215632066" Date: Sun, 5 Mar 2017 18:20:27 +0100 (CET) From: Julia Lawall X-X-Sender: jll@hadrien To: Julia Lawall cc: simran singhal , oleg.drokin@intel.com, andreas.dilger@intel.com, jsimmons@infradead.org, gregkh@linuxfoundation.org, lustre-devel@lists.lustre.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, outreachy-kernel@googlegroups.com Subject: Re: [Outreachy kernel] [PATCH 5/5] staging: lustre: osc_page.c: Use list_for_each_entry_safe In-Reply-To: Message-ID: References: <1488733610-22289-1-git-send-email-singhalsimran0@gmail.com> <1488733610-22289-6-git-send-email-singhalsimran0@gmail.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3956 Lines: 117 On Sun, 5 Mar 2017, Julia Lawall wrote: > > > On Sun, 5 Mar 2017, simran singhal wrote: > > > Doubly linked lists which are iterated using list_empty > > and list_entry macros have been replaced with list_for_each_entry_safe > > macro. > > This makes the iteration simpler and more readable. > > > > This patch replaces the while loop containing list_empty and list_entry > > with list_for_each_entry_safe. > > list_for_each_entry_safe is only needed when the current element is > removed from the list within the loop body. If that is not the case, you > can just use list_for_each_entry. Sorry, my comment was likely completely off the mark here. I was thinking that the original code was using list_for_each. With the while (!list_empty pattern, the safe version is definitely needed. julia > > julia > > > > > > This was done with Coccinelle. > > > > @@ > > expression E1; > > identifier I1, I2; > > type T; > > iterator name list_for_each_entry_safe; > > @@ > > > > T *I1; > > + T *tmp; > > ... > > - while (list_empty(&E1) == 0) > > + list_for_each_entry_safe (I1, tmp, &E1, I2) > > { > > ...when != T *I1; > > - I1 = list_entry(E1.next, T, I2); > > ... > > } > > > > Signed-off-by: simran singhal > > --- > > drivers/staging/lustre/lustre/osc/osc_page.c | 11 ++++------- > > 1 file changed, 4 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/staging/lustre/lustre/osc/osc_page.c b/drivers/staging/lustre/lustre/osc/osc_page.c > > index ed8a0dc..e8b974f 100644 > > --- a/drivers/staging/lustre/lustre/osc/osc_page.c > > +++ b/drivers/staging/lustre/lustre/osc/osc_page.c > > @@ -542,6 +542,7 @@ long osc_lru_shrink(const struct lu_env *env, struct client_obd *cli, > > struct cl_object *clobj = NULL; > > struct cl_page **pvec; > > struct osc_page *opg; > > + struct osc_page *tmp; > > int maxscan = 0; > > long count = 0; > > int index = 0; > > @@ -572,7 +573,7 @@ long osc_lru_shrink(const struct lu_env *env, struct client_obd *cli, > > if (force) > > cli->cl_lru_reclaim++; > > maxscan = min(target << 1, atomic_long_read(&cli->cl_lru_in_list)); > > - while (!list_empty(&cli->cl_lru_list)) { > > + list_for_each_entry_safe(opg, tmp, &cli->cl_lru_list, ops_lru) { > > struct cl_page *page; > > bool will_free = false; > > > > @@ -582,8 +583,6 @@ long osc_lru_shrink(const struct lu_env *env, struct client_obd *cli, > > if (--maxscan < 0) > > break; > > > > - opg = list_entry(cli->cl_lru_list.next, struct osc_page, > > - ops_lru); > > page = opg->ops_cl.cpl_page; > > if (lru_page_busy(cli, page)) { > > list_move_tail(&opg->ops_lru, &cli->cl_lru_list); > > @@ -1043,6 +1042,7 @@ unsigned long osc_cache_shrink_scan(struct shrinker *sk, > > { > > struct client_obd *stop_anchor = NULL; > > struct client_obd *cli; > > + struct client_obd *tmp; > > struct lu_env *env; > > long shrank = 0; > > u16 refcheck; > > @@ -1059,10 +1059,7 @@ unsigned long osc_cache_shrink_scan(struct shrinker *sk, > > return SHRINK_STOP; > > > > spin_lock(&osc_shrink_lock); > > - while (!list_empty(&osc_shrink_list)) { > > - cli = list_entry(osc_shrink_list.next, struct client_obd, > > - cl_shrink_list); > > - > > + list_for_each_entry_safe(cli, tmp, &osc_shrink_list, cl_shrink_list) { > > if (!stop_anchor) > > stop_anchor = cli; > > else if (cli == stop_anchor) > > -- > > 2.7.4 > > > > -- > > You received this message because you are subscribed to the Google Groups "outreachy-kernel" group. > > To unsubscribe from this group and stop receiving emails from it, send an email to outreachy-kernel+unsubscribe@googlegroups.com. > > To post to this group, send email to outreachy-kernel@googlegroups.com. > > To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/1488733610-22289-6-git-send-email-singhalsimran0%40gmail.com. > > For more options, visit https://groups.google.com/d/optout. > > >