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Date:   Tue, 7 Jun 2022 07:34:54 +0800
From:   Baoquan He <bhe@redhat.com>
To:     Uladzislau Rezki <urezki@gmail.com>, akpm@linux-foundation.org
Cc:     npiggin@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/5] mm/vmalloc: remove the unnecessary type check
Message-ID: <20220606233454.GB234358@MiWiFi-R3L-srv>
References: <20220606083909.363350-1-bhe@redhat.com>
 <20220606083909.363350-2-bhe@redhat.com>
 <Yp5lM0j1JdceUEjw@pc638.lan>
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On 06/06/22 at 10:36pm, Uladzislau Rezki wrote:
> > In function adjust_va_to_fit_type(), it checks all values of passed
> > in fit type, including NOTHING_FIT in the else branch. In fact, it's
> > unnecessary to check NOTHING_FIT since the check has been done before
> > adjust_va_to_fit_type() is called in all call sites. So clean it up.
> > 
> > Signed-off-by: Baoquan He <bhe@redhat.com>
> > ---
> >  mm/vmalloc.c | 2 --
> >  1 file changed, 2 deletions(-)
> > 
> > diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> > index 07db42455dd4..b7a138ab7b79 100644
> > --- a/mm/vmalloc.c
> > +++ b/mm/vmalloc.c
> > @@ -1418,8 +1418,6 @@ adjust_va_to_fit_type(struct vmap_area *va,
> >  		 * Shrink this VA to remaining size.
> >  		 */
> >  		va->va_start = nva_start_addr + size;
> > -	} else {
> > -		return -1;
> >  	}
> >  
> >  	if (type != FL_FIT_TYPE) {
> > -- 
> > 2.34.1
> > 
> Why not just invoke the classify_va_fit_type() inside the adjust_va_to_fit_type()?
> In this case we do not need to rely on upper-stack checks and the split logic 
> becomes fully implemented in one solid function.

Ah, that's much better, let me post a new one. Thanks a lot.