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Tue, 07 Nov 2023 17:28:37 -0800 (PST) Received: from google.com ([2401:fa00:8f:203:2fe:d436:c346:6fcf]) by smtp.gmail.com with ESMTPSA id 2-20020a17090a01c200b002609cadc56esm475764pjd.11.2023.11.07.17.28.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Nov 2023 17:28:36 -0800 (PST) Date: Wed, 8 Nov 2023 10:28:23 +0900 From: Sergey Senozhatsky To: Ankur Arora Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de, peterz@infradead.org, torvalds@linux-foundation.org, paulmck@kernel.org, linux-mm@kvack.org, x86@kernel.org, akpm@linux-foundation.org, luto@kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, willy@infradead.org, mgorman@suse.de, jon.grimm@amd.com, bharata@amd.com, raghavendra.kt@amd.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com, jgross@suse.com, andrew.cooper3@citrix.com, mingo@kernel.org, bristot@kernel.org, mathieu.desnoyers@efficios.com, geert@linux-m68k.org, glaubitz@physik.fu-berlin.de, anton.ivanov@cambridgegreys.com, mattst88@gmail.com, krypton@ulrich-teichert.org, rostedt@goodmis.org, David.Laight@aculab.com, richard@nod.at, mjguzik@gmail.com, SeongJae Park , Mike Kravetz , Muchun Song , Andrey Ryabinin , Marco Elver , Catalin Marinas , Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Naoya Horiguchi , Miaohe Lin , David Hildenbrand , Oscar Salvador , Mike Rapoport , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Dennis Zhou , Tejun Heo , Christoph Lameter , Hugh Dickins , Pekka Enberg , David Rientjes , Joonsoo Kim , Vlastimil Babka , Vitaly Wool , Minchan Kim , Sergey Senozhatsky , Seth Jennings , Dan Streetman Subject: Re: [RFC PATCH 68/86] treewide: mm: remove cond_resched() Message-ID: <20231108012823.GD11577@google.com> References: <20231107215742.363031-1-ankur.a.arora@oracle.com> <20231107230822.371443-1-ankur.a.arora@oracle.com> <20231107230822.371443-12-ankur.a.arora@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231107230822.371443-12-ankur.a.arora@oracle.com> X-Rspamd-Queue-Id: 999F1140003 X-Rspam-User: X-Stat-Signature: 83n574xkcxemce7isjesetrp74pefpc9 X-Rspamd-Server: rspam03 X-HE-Tag: 1699406918-363216 X-HE-Meta: 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 ZatFieHL Ql8woocuFsNED5LydJ3xRe02KExCz1cW9h8z2bQsIuU0HoeUvN/uyR0LN6TOZXf8inmMJ6Exb3BsKMVK2CSVEHVhtm4Ft8xWJKDxC9n6a8ZcWM44KAZ+l/f5r9WqGlHX/qNmOzN2KdIWURyGn5EINvYFuR0J0M/9Yt1LvFiY7OEAocErwGyUN8p9xgWiCNxBgaITmQzsWfpTKP6pwZs32q5+X4oKhKD2eu2X+DzovyFymOxC2AR440/Ml6Gfv/vmgUBg4dEQuyunEg7N/8wGfRrgrTUP0XHbHTS3DdF/GM5zg6iTJZ+vhfE0Ij9oNCcTqys5jy8jLQB1gxR/1Q32SUSDoXji0g1Pj7iB4HaPFmW2zDRphuXflSaMpPFmqNiNTtyimH+BxxjvRIcOQ4nk0mkft/PpTD4hsmCLo68MUQE5foiyfLK3vU11dcQ== 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: List-Subscribe: List-Unsubscribe: On (23/11/07 15:08), Ankur Arora wrote: [..] > +++ b/mm/zsmalloc.c > @@ -2029,7 +2029,6 @@ static unsigned long __zs_compact(struct zs_pool *pool, > dst_zspage = NULL; > > spin_unlock(&pool->lock); > - cond_resched(); > spin_lock(&pool->lock); > } > } I'd personally prefer to have a comment explaining why we do that spin_unlock/spin_lock sequence, which may look confusing to people. Maybe would make sense to put a nice comment in all similar cases. For instance: rcu_read_unlock(); - cond_resched(); rcu_read_lock();