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Mon, 21 Nov 2022 23:19:18 -0800 (PST) Date: Tue, 22 Nov 2022 16:19:13 +0900 From: Sergey Senozhatsky To: Johannes Weiner Cc: Sergey Senozhatsky , 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=1669101560; a=rsa-sha256; cv=none; b=kH0X3wLEoEwJ3QEKGJ8h4b6BeLNQYXiOYnaslF2cRelYqLdsCJwOiB+j7OAMPy6vbChkzp fZN99uUmpg00qQxOrjhXGMgX0ZuNdI7njVBcjV8W4l1QeWKPUK9NYbjQHuc7rO+O0VLy9K T29Bg75tiy66/ho7XTt+X54Z2tDfwAc= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=ev5UBIGz; 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dmarc=pass (policy=none) header.from=chromium.org X-Rspam-User: X-Stat-Signature: dpychde9r4hhsm5tk5jn4iye3o6fjzyx X-HE-Tag: 1669101559-548263 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 (22/11/22 02:10), Johannes Weiner wrote: > > 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? That would mean that all lru pages constantly have locked objects and we can only make partial progress. > I don't see what the problem with limited retrying in > zs_reclaim_page() is. It's robust and has worked for years. No problem with it, just asking.