From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id AD476C4167B for ; Thu, 30 Nov 2023 00:21:41 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3B3CA6B0096; Wed, 29 Nov 2023 19:21:41 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 363DF6B009C; Wed, 29 Nov 2023 19:21:41 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 22BCB6B00A7; Wed, 29 Nov 2023 19:21:41 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 0ED856B0096 for ; Wed, 29 Nov 2023 19:21:41 -0500 (EST) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id C775D406F0 for ; Thu, 30 Nov 2023 00:21:40 +0000 (UTC) X-FDA: 81512717160.09.6B817D3 Received: from mail-io1-f53.google.com (mail-io1-f53.google.com [209.85.166.53]) by imf01.hostedemail.com (Postfix) with ESMTP id 1915A40003 for ; Thu, 30 Nov 2023 00:21:37 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=IzTksa9s; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf01.hostedemail.com: domain of nphamcs@gmail.com designates 209.85.166.53 as permitted sender) smtp.mailfrom=nphamcs@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1701303698; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=8sEYAfmnmUKDzXdKzmpSP1T6NxdrFel4xsutg1ntZcg=; b=X0CoAu6NKhQH3vTRclD7t9/IaTmLvyOoCIa5wgIZl53dU5BOLgPmZgBXgZtccTCZTXPSys CPjq2e9Y70saoouBGBF1ss4CCqN8r7wM2Vx3Lnp0o7cfvLKUw02afd7yHOvnD4VtV+mQBd j+MJTQE3BfOj303gnA8q+R7HQXjXYrc= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=IzTksa9s; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf01.hostedemail.com: domain of nphamcs@gmail.com designates 209.85.166.53 as permitted sender) smtp.mailfrom=nphamcs@gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1701303698; a=rsa-sha256; cv=none; b=HkEdalDXmBToYl1vW+XahIjhm1Emaqj+75YFU3dr5YaYMXXTAtVgC1rTPJla8gZ7bCNUT7 d7EI+FfhIfVNhUyLULpdjm4Lnv+/S5pIvFVywnr792glceFJGUoMJZe6l516hD6AvIqcCD s7bRg3TtBFGzk6Xa+scZVFwrcce2cUs= Received: by mail-io1-f53.google.com with SMTP id ca18e2360f4ac-7b3708b3eacso6597839f.2 for ; Wed, 29 Nov 2023 16:21:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1701303697; x=1701908497; darn=kvack.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=8sEYAfmnmUKDzXdKzmpSP1T6NxdrFel4xsutg1ntZcg=; b=IzTksa9sxjdEIjrhEBWb7nRvPh2abrXrixEn48oxG2XpAr4T0VovD96ywiy8dhvV7w 309DttEHmv2SSq/OM57xtE+Ch/yDdrvFi9Ulv2BqQ8yQoHyj0y1n7BMz5N00r1xwmToi WXD8vC4JySzSeNB6rhUiE+zCVbpRxJAy21LE1TrIExJIeQ013TKbyOs8Z1i0Ht1V7A89 BgJhbXK8Z7rJjjENH3KpaiB7U8DRJLaUFGBHBTQkj4i3eQa6xWieepYsRKd3HxtPn1eN 0Kw4o7mgwfxGUjPBwpzreu2Ghk4m53+BtIUUU9sa8FACu2FGNhgSMxycNBUeuka6P5Ck tvsQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701303697; x=1701908497; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=8sEYAfmnmUKDzXdKzmpSP1T6NxdrFel4xsutg1ntZcg=; b=k8uQ0ChL+WjPykAzrABu2yxmQbi48uFhSIZdUIOUFv06rAq1vQaWPKoG39i1aLMSR4 HYlspv8mBK0VFqqIgFT6MMVPRAnOtsDMj6vLQEyLRNKiWsHfkNmcT8PSopklqBG6Y1nz njrvPaWUzUxg/4J1QAZq1YqWTr/kaIF8SWx43ZCAAcpfsklyyvo9ubBpW9AWatQHrU3R 3p2Z1weLQYU/bo0zRavVMy4GU1fFXw74LiU8tW7swtdJFIIMKKD/NTLQrQ1u74WCUBH3 vWtRmb2F/d3Msi/1efW/rfJ+FvwbI9V/g3q1vsAj7ioZpqqsP9+5cS/PYiwVLg3g7pqC SpIg== X-Gm-Message-State: AOJu0YzVz2TkouGQzRCgw8MapGZ8Q5o5nlXjjylceKfZeXBLr2c5TxvL KtyLp+I9n8kMp+IotnGMN+bGQSUDW6k5/27PZ1g= X-Google-Smtp-Source: AGHT+IFnjon5ckFouO3ILdmOgn+ew1aPuvqBrEyBZkvxwT6MjHsyijlRuwmCEMmG8avlJLyEGPgvzflmo9ozXUtwHyo= X-Received: by 2002:a6b:e602:0:b0:79f:d04d:ce5a with SMTP id g2-20020a6be602000000b0079fd04dce5amr17455738ioh.2.1701303697230; Wed, 29 Nov 2023 16:21:37 -0800 (PST) MIME-Version: 1.0 References: <20231127234600.2971029-1-nphamcs@gmail.com> <20231127234600.2971029-4-nphamcs@gmail.com> <20231129151721.GC135852@cmpxchg.org> In-Reply-To: <20231129151721.GC135852@cmpxchg.org> From: Nhat Pham Date: Wed, 29 Nov 2023 16:21:26 -0800 Message-ID: Subject: Re: [PATCH v7 3/6] zswap: make shrinking memcg-aware To: Johannes Weiner Cc: akpm@linux-foundation.org, cerasuolodomenico@gmail.com, yosryahmed@google.com, sjenning@redhat.com, ddstreet@ieee.org, vitaly.wool@konsulko.com, mhocko@kernel.org, roman.gushchin@linux.dev, shakeelb@google.com, muchun.song@linux.dev, chrisl@kernel.org, linux-mm@kvack.org, kernel-team@meta.com, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, shuah@kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 1915A40003 X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: e6b8tunq4bsu551jyhx75x999npbqckz X-HE-Tag: 1701303697-927098 X-HE-Meta: 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 bGrfpmep kyzJzRiBawq8zY6flpL/gPOlMHiuflUmTTam/MmPbotqmBxjajd08UvoStsalsjPq4Les5kzFYgfHULq7Ed5/eU9blM0AUuitB3wTXZlZphcAwXpsdsHGaEMDQw4a8eqT6Mr39JYWi/gbcnv0rGPD3JiAEnoI1/BHZgsgvzdqZBJb+OxGHTbZ7NK/vZNEYDucMWzgXo4ZVScvtylZswaWXinnlZ33jFyKKMMaJXZM1U3182ljrWrPHUZ0nqG3E0APbX4PupYnKgVlhHJaQC70/nZe6Al3zm7wff6u2ZilwkuqbTCtBEHLlpM2pfSQWbxhjYkNRtp44GeLN4SZp/n7D8qOCxxTu/kS6+VQZDH+Ytq24v0vjjkdLgpFhpnIHh0c9sYaWIxRV3j04jFxCO7IVs9EdwUsUaqWQfys 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 Wed, Nov 29, 2023 at 7:17=E2=80=AFAM Johannes Weiner wrote: > > On Mon, Nov 27, 2023 at 03:45:57PM -0800, Nhat Pham wrote: > > static void shrink_worker(struct work_struct *w) > > { > > struct zswap_pool *pool =3D container_of(w, typeof(*pool), > > shrink_work); > > + struct mem_cgroup *memcg; > > int ret, failures =3D 0; > > > > + /* global reclaim will select cgroup in a round-robin fashion. */ > > do { > > - ret =3D zswap_reclaim_entry(pool); > > - if (ret) { > > - zswap_reject_reclaim_fail++; > > - if (ret !=3D -EAGAIN) > > - break; > > + spin_lock(&zswap_pools_lock); > > + memcg =3D pool->next_shrink =3D > > + mem_cgroup_iter_online(NULL, pool->next_shrink, N= ULL, true); > > + > > + /* full round trip */ > > + if (!memcg) { > > + spin_unlock(&zswap_pools_lock); > > if (++failures =3D=3D MAX_RECLAIM_RETRIES) > > break; > > + > > + goto resched; > > } > > + > > + /* > > + * Acquire an extra reference to the iterated memcg in ca= se the > > + * original reference is dropped by the zswap offlining c= allback. > > + */ > > + css_get(&memcg->css); > > struct mem_cgroup isn't defined when !CONFIG_MEMCG. This needs a > mem_cgroup_get() wrapper and a dummy function for no-memcg builds. I got this exact same issue a couple of versions ago, but it was hidden behind another helper function which can be implemented as a no-op in the case of !CONFIG_MEMCG, so I forgot about it until now. It always strikes me a bit weird that we have mem_cgroup_put() but not an equivalent get - let me correct that. > > With that fixed, though, everything else looks good to me: > > Acked-by: Johannes Weiner Thanks for the review, Johannes!