From mboxrd@z Thu Jan 1 00:00:00 1970 From: Baolin Wang Subject: Re: [PATCH v3 3/4] mm: hugetlb: change to return bool for isolate_hugetlb() Date: Thu, 16 Feb 2023 10:04:29 +0800 Message-ID: References: <20230215202548.92462-1-sj@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20230215202548.92462-1-sj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: SeongJae Park Cc: akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, roman.gushchin-fxUVXftIFDnyG1zEObXtfA@public.gmane.org, shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, muchun.song-fxUVXftIFDnyG1zEObXtfA@public.gmane.org, naoya.horiguchi-YMj9X0ASwKA@public.gmane.org, linmiaohe-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, david-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, osalvador-l3A5Bk7waGM@public.gmane.org, mike.kravetz-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, willy-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, damon-cunTk1MwBs/YUNznpcFYbw@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org On 2/16/2023 4:25 AM, SeongJae Park wrote: > On Wed, 15 Feb 2023 18:39:36 +0800 Baolin Wang wrote: > >> Now the isolate_hugetlb() only returns 0 or -EBUSY, and most users did not >> care about the negative value, thus we can convert the isolate_hugetlb() >> to return a boolean value to make code more clear when checking the >> hugetlb isolation state. Moreover converts 2 users which will consider >> the negative value returned by isolate_hugetlb(). >> >> No functional changes intended. >> >> Signed-off-by: Baolin Wang >> Acked-by: David Hildenbrand >> --- > [...] >> include/linux/hugetlb.h | 6 +++--- >> mm/hugetlb.c | 13 ++++++++----- >> mm/memory-failure.c | 2 +- >> mm/mempolicy.c | 2 +- >> mm/migrate.c | 7 +++---- >> 5 files changed, 16 insertions(+), 14 deletions(-) >> > [...] >> diff --git a/mm/hugetlb.c b/mm/hugetlb.c >> index 3a01a9dbf445..16513cd23d5d 100644 >> --- a/mm/hugetlb.c >> +++ b/mm/hugetlb.c >> @@ -2925,13 +2925,16 @@ static int alloc_and_dissolve_hugetlb_folio(struct hstate *h, >> */ >> goto free_new; >> } else if (folio_ref_count(old_folio)) { >> + bool isolated; >> + >> /* >> * Someone has grabbed the folio, try to isolate it here. >> * Fail with -EBUSY if not possible. >> */ >> spin_unlock_irq(&hugetlb_lock); >> - ret = isolate_hugetlb(old_folio, list); >> + isolated = isolate_hugetlb(old_folio, list); >> spin_lock_irq(&hugetlb_lock); >> + ret = isolated ? 0 : -EBUSY; >> goto free_new; > > Nit. I'd personally prefer to set 'ret' before entering this critical section > to keep the section short, but this would be just a mean comment that wouldn't > worth request respin. Yes, good catch. And I see Andrew has helped to do this (Thanks Andrew). Thanks for reviewing.