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Mon, 06 Jun 2022 13:46:38 -0700 (PDT) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Mon, 6 Jun 2022 22:46:36 +0200 To: Baoquan He Cc: akpm@linux-foundation.org, npiggin@gmail.com, urezki@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/5] mm/vmalloc: remove the redundant boundary check Message-ID: References: <20220606083909.363350-1-bhe@redhat.com> <20220606083909.363350-3-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220606083909.363350-3-bhe@redhat.com> X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: E590240004 X-Stat-Signature: diryydoe7ya7zux8khpc8ymyga9cmt5f Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=myTkGQ7V; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf07.hostedemail.com: domain of urezki@gmail.com designates 209.85.167.41 as permitted sender) smtp.mailfrom=urezki@gmail.com X-HE-Tag: 1654548385-209392 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: On Mon, Jun 06, 2022 at 04:39:06PM +0800, Baoquan He wrote: > In function find_va_links(), when traversing the vmap_area tree, the > comparing to check if the passed in 'va' is above or below 'tmp_va' > is redundant, assuming both 'va' and 'tmp_va' has ->va_start <= ->va_end. > > Here, to simplify the checking as code change. > > Signed-off-by: Baoquan He > --- > mm/vmalloc.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index b7a138ab7b79..c7e1634ff2b9 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -874,11 +874,9 @@ find_va_links(struct vmap_area *va, > * Trigger the BUG() if there are sides(left/right) > * or full overlaps. > */ > - if (va->va_start < tmp_va->va_end && > - va->va_end <= tmp_va->va_start) > + if (va->va_end <= tmp_va->va_start) > link = &(*link)->rb_left; > - else if (va->va_end > tmp_va->va_start && > - va->va_start >= tmp_va->va_end) > + else if (va->va_start >= tmp_va->va_end) > link = &(*link)->rb_right; > else { > WARN(1, "vmalloc bug: 0x%lx-0x%lx overlaps with 0x%lx-0x%lx\n", > -- > 2.34.1 > Make sense to me: Reviewed-by: Uladzislau Rezki (Sony) -- Uladzislau Rezki