From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout.gmx.net (mout.gmx.net [212.227.17.21]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A6A5D2C80 for ; Tue, 30 Nov 2021 18:00:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1638295203; bh=p0H2cqMkifqjvSF0fOMCU23FVPx2ReNpJKrlUcqatUI=; h=X-UI-Sender-Class:Subject:From:To:Cc:Date:In-Reply-To:References; b=K5wHVjQFW3Vizg/YlVvPHdM5z3L30o5/AVVQuaWC23PIDvrRx/bfCyJhBzNI4WX24 mVXqxuljiZRLJhfdzMQP+Fki6NRDpmRp0+yOOy3hAQSkhBz0C1tfpKOlUS0iA2eOjl E/j2MFt9ZFlY+PB7s4ls6ujzAXIVodSZHDidqEH0= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from homer.fritz.box ([185.146.50.175]) by mail.gmx.net (mrgmx104 [212.227.17.168]) with ESMTPSA (Nemesis) id 1MsYux-1mcWLY0Q5j-00u1ej; Tue, 30 Nov 2021 19:00:03 +0100 Message-ID: Subject: Re: [PATCH 1/1] mm: vmscan: Reduce throttling due to a failure to make progress From: Mike Galbraith To: Mel Gorman , Alexey Avramov Cc: Andrew Morton , Michal Hocko , Vlastimil Babka , Rik van Riel , Darrick Wong , regressions@lists.linux.dev, Linux-fsdevel , Linux-MM , LKML Date: Tue, 30 Nov 2021 18:59:58 +0100 In-Reply-To: <20211130172754.GS3366@techsingularity.net> References: <20211125151853.8540-1-mgorman@techsingularity.net> <20211127011246.7a8ac7b8@mail.inbox.lv> <20211129150117.GO3366@techsingularity.net> <20211201010348.31e99637@mail.inbox.lv> <20211130172754.GS3366@techsingularity.net> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.42.1 Precedence: bulk X-Mailing-List: regressions@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:RpBUBEAGZmeNkXxqfTXCYJ3JGdKKlx/k6qsoxqkn+eNZyGA17fS 6A0ECgR6AmCvDIINwTQw9d1a9fWix5WcL+PFG6LwZuoc+MPZtHvKjTta2iYTLM3ApLzUbrp VMi4+tOapr0qwJuHz7v+a9vPW7AOJcr6+GJ0ZIKack7d13WWCT2pF6ORBJH36TMO22VgnY3 1aFU7c4j4KNX9Vz0ycPGw== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1;V03:K0:aGQmldvLPl0=:NQTJciD5A+GpoR/z/5yBt+ QOsVJt5cfxoNYpfuMxn+P4TZmJYIfkJMSLRBobj46VN6YKawDdCdOGm9dfcieUtAZbOjExRKP TGZ7J6hrhzXOBINZ47sKO2tFl5PrcxsW7rJPR9vnpVdl9on4/8sXZdoM9+ecAHap+S/r6Im69 K0SLpbd+nQJp79dHkj3iLTEWhYa2U+hfy/j7DOJpBTVsyw6GcOkrhtwRlteT0kwXgzCfztArW ByPG4L6vbjSGQYzXjLJJXpXglcbNN71MAsvq10ZmhsaY8tzwB49+lyijjEfQL3fxUFCaJ3lfl l7ICZ0CzVXnfGSyt59aChCyZ5wH/BFSskNz2ajXNtaBReSsZYxKUJgJtImPREF8hXOUWPNQYz cs2iIC0I2DtzSCQD2Q1o8/M17Kunu8HLRPWJPGkJ2NXcFEj0FENSInthzRh2t7PQm0CUTmXAO UVOfd6V0acPtxJsZN0QfTtLZ8omSMAAWH430IEISln8kt+yV+VCksZyzd2WS2g0UvSDWAw0gO QeZVgt0yz1VIDlZd2dqEk3zEQ5EZqlXfpWg/kP2j9eLRgEV5IiVZ07lpcMeWTyo7g8sICcgKR NGQfPqrMlY5X007xvvJCUssyNk8CWfzmU+wZRrqIbvWKFyQ8hgKKxTVVHVJPyjJGIRMnHhX5L yR6BoWVaWNXSCIV5LY+eeedzTJYaVNt75+qvfa1yzUxsPCXkqqYBSItt5di8SkTJHtrd3y/7h 0s5GKo4YiCcNWTKTgobiIavBdfHcnox9rTQKCf8tNfXKLvRy4ER3CsKe5bwAfjk+E0dy1Zhbf leJ9Z2kOHmwquwZc+/gBEsOgoDpnRh5Vn6tP1KkeqUH5ke+ZuLW+Ane1W/6ymURfvVfNcXDDp TyS8iV0uN0Oz0zFsi0v1P8Cxrfl6dMM8DjznjISkhgD0SxIjhVakefBiitS+TE3+8QKQm4UES cU4xPIhOVmemF3TlUXXQZ6Epawlw++CjyRnxBewZwuSaTxOTYpeSDjxGAzikpv9Uw4CMWCg9V IeIhEuO4nNBlUmxLXB5tt1jn3iCDx3oR+cTY91W/h+XiD0G7xUVi0pNy0lQ/XCe+rBrY5w1Jp dMwp7Xc2nv4mfY= On Tue, 2021-11-30 at 17:27 +0000, Mel Gorman wrote: > > Obviously a fairly different experience and most likely due to the > underlying storage. I bet a virtual nickle this is the sore spot. =2D-- mm/vmscan.c | 10 ++++++++++ 1 file changed, 10 insertions(+) =2D-- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3360,7 +3360,17 @@ static void shrink_node(pg_data_t *pgdat if (!current_is_kswapd() && current_may_throttle() && !sc->hibernation_mode && test_bit(LRUVEC_CONGESTED, &target_lruvec->flags)) +#if 0 reclaim_throttle(pgdat, VMSCAN_THROTTLE_WRITEBACK); +#else + /* + * wait_iff_congested() used to live here and was + * _apparently_ a misspelled cond_resched()????? + * In any case, we are most definitely NOT starting + * any IO in reclaim_throttle(), so why bother? + */ + cond_resched(); +#endif if (should_continue_reclaim(pgdat, sc->nr_reclaimed - nr_reclaimed, sc))