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Mon, 28 Feb 2022 23:59:07 -0800 (PST) From: Xiaomeng Tong To: torvalds@linux-foundation.org Cc: arnd@arndb.de, jakobkoschel@gmail.com, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, keescook@chromium.org, jannh@google.com, linux-kbuild@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, Xiaomeng Tong Subject: [PATCH 3/6] kernel: remove iterator use outside the loop Date: Tue, 1 Mar 2022 15:58:36 +0800 Message-Id: <20220301075839.4156-4-xiam0nd.tong@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220301075839.4156-1-xiam0nd.tong@gmail.com> References: <20220301075839.4156-1-xiam0nd.tong@gmail.com> X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 16E9D40004 X-Stat-Signature: rodz6jt8crny5inq53no911fh7ifhc8g Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=gVxF1LdS; spf=pass (imf12.hostedemail.com: domain of xiam0nd.tong@gmail.com designates 209.85.215.169 as permitted sender) smtp.mailfrom=xiam0nd.tong@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-HE-Tag: 1646121548-834121 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Demonstrations for: - list_for_each_entry_inside - list_for_each_entry_continue_inside - list_for_each_entry_safe_continue_inside Signed-off-by: Xiaomeng Tong --- kernel/power/snapshot.c | 28 ++++++++++++++++------------ kernel/signal.c | 6 +++--- 2 files changed, 19 insertions(+), 15 deletions(-) diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 330d49937..75958b5fa 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -625,16 +625,18 @@ static int create_mem_extents(struct list_head *list, gfp_t gfp_mask) for_each_populated_zone(zone) { unsigned long zone_start, zone_end; - struct mem_extent *ext, *cur, *aux; + struct mem_extent *me = NULL; zone_start = zone->zone_start_pfn; zone_end = zone_end_pfn(zone); - list_for_each_entry(ext, list, hook) - if (zone_start <= ext->end) + list_for_each_entry_inside(ext, struct mem_extent, list, hook) + if (zone_start <= ext->end) { + me = ext; break; + } - if (&ext->hook == list || zone_end < ext->start) { + if (!me || zone_end < me->start) { /* New extent is necessary */ struct mem_extent *new_ext; @@ -645,23 +647,25 @@ static int create_mem_extents(struct list_head *list, gfp_t gfp_mask) } new_ext->start = zone_start; new_ext->end = zone_end; - list_add_tail(&new_ext->hook, &ext->hook); + if (!me) + list_add_tail(&new_ext->hook, list); + else + list_add_tail(&new_ext->hook, &me->hook); continue; } /* Merge this zone's range of PFNs with the existing one */ - if (zone_start < ext->start) - ext->start = zone_start; - if (zone_end > ext->end) - ext->end = zone_end; + if (zone_start < me->start) + me->start = zone_start; + if (zone_end > me->end) + me->end = zone_end; /* More merging may be possible */ - cur = ext; - list_for_each_entry_safe_continue(cur, aux, list, hook) { + list_for_each_entry_safe_continue_inside(cur, aux, me, list, hook) { if (zone_end < cur->start) break; if (zone_end < cur->end) - ext->end = cur->end; + me->end = cur->end; list_del(&cur->hook); kfree(cur); } diff --git a/kernel/signal.c b/kernel/signal.c index 9b04631ac..da2c20de1 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -711,7 +711,7 @@ static int dequeue_synchronous_signal(kernel_siginfo_t *info) { struct task_struct *tsk = current; struct sigpending *pending = &tsk->pending; - struct sigqueue *q, *sync = NULL; + struct sigqueue *sync = NULL; /* * Might a synchronous signal be in the queue? @@ -722,7 +722,7 @@ static int dequeue_synchronous_signal(kernel_siginfo_t *info) /* * Return the first synchronous signal in the queue. */ - list_for_each_entry(q, &pending->list, list) { + list_for_each_entry_inside(q, struct sigqueue, &pending->list, list) { /* Synchronous signals have a positive si_code */ if ((q->info.si_code > SI_USER) && (sigmask(q->info.si_signo) & SYNCHRONOUS_MASK)) { @@ -735,7 +735,7 @@ static int dequeue_synchronous_signal(kernel_siginfo_t *info) /* * Check if there is another siginfo for the same signal. */ - list_for_each_entry_continue(q, &pending->list, list) { + list_for_each_entry_continue_inside(q, sync, &pending->list, list) { if (q->info.si_signo == sync->info.si_signo) goto still_pending; }