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Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , linux-mm@kvack.org, linux-kernel@vger.kernel.org, usamaarif642@gmail.com, kernel-team@meta.com Subject: Re: [PATCH 0/2] mm: thp: reduce unnecessary start_stop_khugepaged() calls Message-ID: <8042a515-e88a-4b4c-a5ab-d4eb6deaf4b3@lucifer.local> References: <20260304-thp_logs-v1-0-59038218a253@debian.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Stat-Signature: d1zgtcmk7drnkbr49nyt3ugyb8bzx6ss X-Rspam-User: X-Rspamd-Queue-Id: 88A671C0006 X-Rspamd-Server: rspam12 X-HE-Tag: 1772714797-376775 X-HE-Meta: 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 TzobUC2R 0hH4FWlTwUToQ4p6oJjkg3jq5UdmrQ0ZAj6bqfTrbSVamIccdj+1Fti5YL2RP8rBhJBkvMSiCQTruF44aBRFbrBaLGn1QprWVxyby7Cycp/4Mhi3pvx2yK3TFf/T/zSoHpzRFmI4bSVguuFH/5mvnk80gpOt9ZOeJi8rsnGJlVPBjheQL0VZSkEUbJkv+S7wQS2T5vPlBwiExt/qArsz7fic1rTexJcrSYm2gQ1gvSkH6EJ3Na+jEPfWL55p86EpTlUzHuWzeMY1VSvc= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Mar 05, 2026 at 12:45:56PM +0000, Lorenzo Stoakes (Oracle) wrote: > On Thu, Mar 05, 2026 at 01:41:33PM +0100, David Hildenbrand (Arm) wrote: > > > > >> + > > >> + /* Check if anything has to be done */ > > >> + if (hugepage_pmd_enabled() == !!khugepaged_thread) > > > > > > This is horrible, better to break out the latter expression as a small static > > > function like: > > > > > > static bool is_khugepaged_thread_running(void) > > > { > > > if (khugepaged_thread) > > > return true; > > > return false; > > > > return khugepaged_thread; > > > > should do the trick, given taht the return type of the function is a bool :) > > Yeah I know :) > > I mean it's subjective, but this form makes it clear that what you're returning > is _not_ a boolean. Sorry obviously meant to say what you're TESTING not what you're RETURNING. > > I was a bit 'meh' when I first saw this pattern, but it's grown on me, sort of a > 'make it so simple you can't get confused' kinda thing. > > > > > > } > > > > -- > > Cheers, > > > > David > > Cheers, Lorenzo