From nobody Sun Jul 14 03:58:07 2024 X-Original-To: freebsd-stable@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4WMBQ52r7Jz5Q59B for ; Sun, 14 Jul 2024 03:58:21 +0000 (UTC) (envelope-from rick.macklem@gmail.com) Received: from mail-ot1-x334.google.com (mail-ot1-x334.google.com [IPv6:2607:f8b0:4864:20::334]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "WR4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4WMBQ371blz40N8 for ; Sun, 14 Jul 2024 03:58:19 +0000 (UTC) (envelope-from rick.macklem@gmail.com) Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20230601 header.b=LkvK89vT; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of rick.macklem@gmail.com designates 2607:f8b0:4864:20::334 as permitted sender) smtp.mailfrom=rick.macklem@gmail.com Received: by mail-ot1-x334.google.com with SMTP id 46e09a7af769-7036e383089so1993094a34.2 for ; Sat, 13 Jul 2024 20:58:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1720929499; x=1721534299; darn=freebsd.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=vABtcgD+ZpCc1GgO9wCHzsJu4c+LLmYLG1m/fF/DBfo=; b=LkvK89vTX3jG3wetkTp4iEBEAdheBq5ZpP0qMpn+KpVmCzLy4JieV3sdhWBa+4Qv+j PpClrlKRnsTmRKfF/M5lQAyr3S56Niu1s4GNl2J2r1s3E6Q7kcEXagnvaUv/zIvMfzXB 1evmss7gGcEyRyP+FGA+NW/VgYlcRLph4Gqv1co6pnSR6L/cElSSv0BywcDFAebORagf TLG83yGDhvtV6fv51wlJL3lI+KUQEN62x1RgW2eD49tOpTDV/5A8VPRi2uGIzFrFU9iW ks30Nis3nIohXmrxphF1yK6IYImKO7or9y7xMwfOi0fqRlxfzey/YPls6noENEm/5IQD 3Xdg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1720929499; x=1721534299; 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=vABtcgD+ZpCc1GgO9wCHzsJu4c+LLmYLG1m/fF/DBfo=; b=tU+HDdPFl8n4cqkecomDVhbGTzmmvDJMDqsvcC/4XkNp3+zNn//YfYlegibWuQwUex V3CFtuBrxHXcAf+7rWVqMfUBESpHet8yKJkvnu3SwB3WxqZ1XyGI4Z5NE747yKSrfN7Y MNn4+8PQDou88Ci3n1mqX+7UQ64UG+VjxxLIRnBMdzwDCEOv2zOOgaCdIWDNWBE8nMQ3 a/RtBKa99Lkg21YNSCT6dyL5LFwJBqPo2x//4VWiFsZOGLfRYBiodhmxf379C7ysVueU 9cD9WSDwx6dd9Wh8o2JxGvUdL/Jj9q3ezOGeXOuB4tIl6HeEk1MDElC10UR1ocWFUiSC LcEw== X-Gm-Message-State: AOJu0YyKF5WLIOjh/L1+4L8iXMmLQxHiwQfvT59PRCM9gcMGZEzSF1B7 7l5EW4DpeH5w0q+YjEVTAA2nauRvLNepHWKCwkIfVJYxn2d+X3NxRbh2RtFEiGAmcdch2LoSJe7 KxJWB9+bFYcG+4JQdkmd78pBv/Yuc X-Google-Smtp-Source: AGHT+IFLmBUh/bm9yrfPm62d8psSe2HjoxMc4JKumdM/fG4JcKPhilEceRsI7NTsjqkewQI7SSkcpnu1yhMZqYwBKhs= X-Received: by 2002:a9d:7b52:0:b0:703:6578:8e2b with SMTP id 46e09a7af769-70375b40067mr18016392a34.23.1720929498624; Sat, 13 Jul 2024 20:58:18 -0700 (PDT) List-Id: Production branch of FreeBSD source code List-Archive: https://lists.freebsd.org/archives/freebsd-stable List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: freebsd-stable@freebsd.org Sender: owner-freebsd-stable@FreeBSD.org MIME-Version: 1.0 References: <26259.12713.114036.564205@hergotha.csail.mit.edu> <26259.17366.276955.824313@hergotha.csail.mit.edu> In-Reply-To: From: Rick Macklem Date: Sat, 13 Jul 2024 20:58:07 -0700 Message-ID: Subject: Re: Possible bug in zfs send or pipe implementation? To: Garrett Wollman Cc: freebsd-stable@freebsd.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spamd-Bar: -- X-Spamd-Result: default: False [-2.99 / 15.00]; SUBJECT_ENDS_QUESTION(1.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.99)[-0.994]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; R_SPF_ALLOW(-0.20)[+ip6:2607:f8b0:4000::/36]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20230601]; MIME_GOOD(-0.10)[text/plain]; RCVD_TLS_LAST(0.00)[]; RCPT_COUNT_TWO(0.00)[2]; TO_DN_SOME(0.00)[]; FREEMAIL_FROM(0.00)[gmail.com]; ARC_NA(0.00)[]; DWL_DNSWL_NONE(0.00)[gmail.com:dkim]; TAGGED_FROM(0.00)[]; MIME_TRACE(0.00)[0:+]; FROM_HAS_DN(0.00)[]; MISSING_XM_UA(0.00)[]; PREVIOUSLY_DELIVERED(0.00)[freebsd-stable@freebsd.org]; TO_MATCH_ENVRCPT_SOME(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; DKIM_TRACE(0.00)[gmail.com:+]; MLMMJ_DEST(0.00)[freebsd-stable@freebsd.org]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; MID_RHS_MATCH_FROMTLD(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; RCVD_COUNT_ONE(0.00)[1]; RCVD_IN_DNSWL_NONE(0.00)[2607:f8b0:4864:20::334:from] X-Rspamd-Queue-Id: 4WMBQ371blz40N8 On Sat, Jul 13, 2024 at 8:50=E2=80=AFPM Rick Macklem wrote: > > On Sat, Jul 13, 2024 at 8:19=E2=80=AFPM Garrett Wollman wrote: > > > > < said: > > > > > # ps axHl > > > should show you what wchan's the processes are waiting on and that mi= ght > > > give you a clue w.r.t. what is happening? > > > > zfs is waiting to write into the pipe and pv (the progress meter) is > > waiting in select. > Just to clarify it, are you saying zfs is sleeping on "pipewr"? If I am reading the code correctly, if it sleeping on "pipewr", it is out of space and that is controlled via: kern.ipc.maxpipekva and you can see what it is using by looking at kern.ipc.pipekva (Unfortunately, I don't think you can change kern.ipc.maxpipekva on the fly= . It looks like it is a loader tunable, so you'd need to reboot to make it larger.) Anyhow, you can take a look at the sysctls. They might help? There is quite a detailed comment in sys/kern/sys_pipe.c related to this. rick > (There is also a msleep() for "pipbww" in pipe_write().) > > rick > > > > > > If is easy to build a kernel from sources and boot that, you could tr= y defining > > > PIPE_NODIRECT in sys/kern/sys_pipe.c and see if that avoids the hangs= ? > > > > It's easy to build a kernel from sources, but not easy to reboot the > > server -- it's being retired shortly, and because of time constraints > > I need to get it drained before the next scheduled outage. > > > > -GAWollman > >