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Mon, 21 Nov 2022 23:09:45 -0800 (PST) Date: Tue, 22 Nov 2022 02:10:11 -0500 From: Johannes Weiner To: Sergey Senozhatsky Cc: Nhat Pham , akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, minchan@kernel.org, ngupta@vflare.org, sjenning@redhat.com, ddstreet@ieee.org, vitaly.wool@konsulko.com Subject: Re: [PATCH v6 6/6] zsmalloc: Implement writeback mechanism for zsmalloc Message-ID: References: <20221119001536.2086599-1-nphamcs@gmail.com> <20221119001536.2086599-7-nphamcs@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1669100987; a=rsa-sha256; cv=none; b=zo56DwT9wGsvCTSbrTadu6zMBs48j6BzdFBASm0+bQFk4Vi6s54w5RIJdYw71FWK5AnIHR KSrfLHb1pMQJEfJuqshYM8y5/+eZE0C9g8+1oul2M84pQsI08k7q1sc2zVsPG/h6bLwlWD oOl5KGnxWadrVHnTCJ3idGFMTq+HZ+4= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=cmpxchg-org.20210112.gappssmtp.com header.s=20210112 header.b=2AS8Iwgu; 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dmarc=pass (policy=none) header.from=cmpxchg.org; spf=pass (imf28.hostedemail.com: domain of hannes@cmpxchg.org designates 209.85.222.176 as permitted sender) smtp.mailfrom=hannes@cmpxchg.org X-Rspam-User: X-HE-Tag: 1669100987-342996 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 Tue, Nov 22, 2022 at 03:35:18PM +0900, Sergey Senozhatsky wrote: > On (22/11/22 01:09), Johannes Weiner wrote: > > On Tue, Nov 22, 2022 at 12:42:20PM +0900, Sergey Senozhatsky wrote: > > > On (22/11/21 22:12), Johannes Weiner wrote: > > > > On Tue, Nov 22, 2022 at 11:15:20AM +0900, Sergey Senozhatsky wrote: > > > > > On (22/11/18 16:15), Nhat Pham wrote: > > [..] > > > > What I meant was: if zs_reclaim_page() makes only partial progress > > > with the current LRU tail zspage and returns -EAGAIN, then we just > > > don't increment `total` and continue looping in zs_zpool_shrink(). > > > > Hm, but it breaks on -EAGAIN, it doesn't continue. > > Yes. "What if it would continue". Would it make sense to not > break on EAGAIN? > > while (total < pages) { > ret = zs_reclaim_page(pool); > if (ret == -EAGAIN) > continue; > if (ret < 0) > break; > total++; > } > > Then we don't need retry loop in zs_reclaim_page(). But that's an indefinite busy-loop? I don't see what the problem with limited retrying in zs_reclaim_page() is. It's robust and has worked for years.