From nobody Thu Mar 10 09:42:17 2022 X-Original-To: dev-commits-src-all@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 D43C71A0FFE1; Thu, 10 Mar 2022 09:42:17 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4KDkcT5bQbz4jDL; Thu, 10 Mar 2022 09:42:17 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1646905337; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=l0NI0H231ZZ3ji+OVbMtnk1CKiDl8R1GzQKk5hYxitY=; b=Pd13XEoqt7//Nnutt49alpnmn7Sj85Wk+DNi2r780ZZvFBx5nu0fDEJBSQQ76qfgA07VRA hYrSR+UBjQuptIFbDGIBzqDoaAh5KLODai08chKtDAcjrlMI+uR8NpNkRAl6SmC3mffw1Q +Hm4y2nshSFqOOtMCLoQtzXRJT8fug0VGy7htoGJ8K+KeThnwdJbuJLjAEYLx3SBwCBGTF ccF85DYTb77ecQ+4fG1NMp4/v7G9fCoCPsVg967iQDaGjZju3FGabb67yHO2hhWQWeoKKW eG9z+VdtdI0qbLN+vQhGAJ8dlCmbINw4qMSDXW/6QDdg0dOaqM+cnVGG9ny73w== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id A120F22963; Thu, 10 Mar 2022 09:42:17 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 22A9gH6f095946; Thu, 10 Mar 2022 09:42:17 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 22A9gHMN095945; Thu, 10 Mar 2022 09:42:17 GMT (envelope-from git) Date: Thu, 10 Mar 2022 09:42:17 GMT Message-Id: <202203100942.22A9gHMN095945@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mateusz Guzik Subject: git: c35ec1efdcb2 - main - vfs: [1/2] fix stalls in vnode reclaim by not requeieing from vnlru List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-all@freebsd.org X-BeenThere: dev-commits-src-all@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: mjg X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: c35ec1efdcb2978bc3b6a0098c2b412be8d33e39 Auto-Submitted: auto-generated ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1646905337; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=l0NI0H231ZZ3ji+OVbMtnk1CKiDl8R1GzQKk5hYxitY=; b=isY51VHuUF4oU8cxCSRGK3ySTvhzIEFdGdvYGEjaHUzfkgSf/7cQptm9lQxUEPwmolqWev JUZN0IoSz7Omy58ooRzpJTzoQ2u8sqtGCP53c7qmDM4aWC6BfEb1HpYglxeB27zHLInGIJ +6jH7hK7GoTHI1SO4am+CnIEvxKwlsv51D/0VlsF4hwL7U2GpWf4vgpdeqexFRbn9Q6UC1 DCU7mqvMbP8LpxXzfquZ8fu3NQ9KuG1izd1oEnVe9Sz42x6Cb/GypO2FuWcTxwgF6iE1y5 as7oeAc1YNhQdOn+gUxvRy7dL5mec9UUuJs54l3D4MT6VUI23qgPgWnOFaHF2w== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1646905337; a=rsa-sha256; cv=none; b=j7Eu2umChgHXOypyYhTcwNLzZW+dmEC+baW/8q3C0VPr8ovA92pplTX1b9U3qBwStyhrMY spdgNBRzXGpIaXmTjsjvZ0cfWJeuSG1frXl0OGQi5FskrfOfOz/9mM2GhNuHludYyPxfH5 +IVxnVHMdoMggqKTr3HkwIUs9I7aAwrul4d2H0crSQ21Lq43wy70Q0wgPZncscg6AHF8H2 ANOApxytbkiDFEKVU74Z3AcCi02Palxwit+/szfK7K1rdDT3o9QncBrPEOThE5zNbIGwJZ /b94wkIaiSKBoXqctSoih+aqJfmOIzEnmUuoGcAmEJOblGPUY5/YuwYA+/ZXPQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N The branch main has been updated by mjg: URL: https://cgit.FreeBSD.org/src/commit/?id=c35ec1efdcb2978bc3b6a0098c2b412be8d33e39 commit c35ec1efdcb2978bc3b6a0098c2b412be8d33e39 Author: Mateusz Guzik AuthorDate: 2022-03-07 10:33:59 +0000 Commit: Mateusz Guzik CommitDate: 2022-03-10 09:41:50 +0000 vfs: [1/2] fix stalls in vnode reclaim by not requeieing from vnlru Reported by: pho --- sys/kern/vfs_subr.c | 55 +++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 45 insertions(+), 10 deletions(-) diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c index afafd02d92b9..436323873f7f 100644 --- a/sys/kern/vfs_subr.c +++ b/sys/kern/vfs_subr.c @@ -113,6 +113,8 @@ static void vn_seqc_init(struct vnode *); static void vn_seqc_write_end_free(struct vnode *vp); static void vgonel(struct vnode *); static bool vhold_recycle_free(struct vnode *); +static void vdropl_recycle(struct vnode *vp); +static void vdrop_recycle(struct vnode *vp); static void vfs_knllock(void *arg); static void vfs_knlunlock(void *arg); static void vfs_knl_assert_lock(void *arg, int what); @@ -1207,11 +1209,11 @@ restart: mtx_unlock(&vnode_list_mtx); if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { - vdrop(vp); + vdrop_recycle(vp); goto next_iter_unlocked; } if (VOP_LOCK(vp, LK_EXCLUSIVE|LK_NOWAIT) != 0) { - vdrop(vp); + vdrop_recycle(vp); vn_finished_write(mp); goto next_iter_unlocked; } @@ -1222,14 +1224,14 @@ restart: (vp->v_object != NULL && vp->v_object->handle == vp && vp->v_object->resident_page_count > trigger)) { VOP_UNLOCK(vp); - vdropl(vp); + vdropl_recycle(vp); vn_finished_write(mp); goto next_iter_unlocked; } counter_u64_add(recycles_count, 1); vgonel(vp); VOP_UNLOCK(vp); - vdropl(vp); + vdropl_recycle(vp); vn_finished_write(mp); done++; next_iter_unlocked: @@ -1613,7 +1615,7 @@ vtryrecycle(struct vnode *vp) CTR2(KTR_VFS, "%s: impossible to recycle, vp %p lock is already held", __func__, vp); - vdrop(vp); + vdrop_recycle(vp); return (EWOULDBLOCK); } /* @@ -1624,7 +1626,7 @@ vtryrecycle(struct vnode *vp) CTR2(KTR_VFS, "%s: impossible to recycle, cannot start the write for %p", __func__, vp); - vdrop(vp); + vdrop_recycle(vp); return (EBUSY); } /* @@ -1636,7 +1638,7 @@ vtryrecycle(struct vnode *vp) VI_LOCK(vp); if (vp->v_usecount) { VOP_UNLOCK(vp); - vdropl(vp); + vdropl_recycle(vp); vn_finished_write(vnmp); CTR2(KTR_VFS, "%s: impossible to recycle, %p is already referenced", @@ -1648,7 +1650,7 @@ vtryrecycle(struct vnode *vp) vgonel(vp); } VOP_UNLOCK(vp); - vdropl(vp); + vdropl_recycle(vp); vn_finished_write(vnmp); return (0); } @@ -3598,8 +3600,8 @@ vdrop(struct vnode *vp) vdropl(vp); } -void -vdropl(struct vnode *vp) +static void __always_inline +vdropl_impl(struct vnode *vp, bool enqueue) { ASSERT_VI_LOCKED(vp, __func__); @@ -3627,6 +3629,39 @@ vdropl(struct vnode *vp) vdbatch_enqueue(vp); } +void +vdropl(struct vnode *vp) +{ + + vdropl_impl(vp, true); +} + +/* + * vdrop a vnode when recycling + * + * This is a special case routine only to be used when recycling, differs from + * regular vdrop by not requeieing the vnode on LRU. + * + * Consider a case where vtryrecycle continuously fails with all vnodes (due to + * e.g., frozen writes on the filesystem), filling the batch and causing it to + * be requeued. Then vnlru will end up revisiting the same vnodes. This is a + * loop which can last for as long as writes are frozen. + */ +static void +vdropl_recycle(struct vnode *vp) +{ + + vdropl_impl(vp, false); +} + +static void +vdrop_recycle(struct vnode *vp) +{ + + VI_LOCK(vp); + vdropl_recycle(vp); +} + /* * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT * flags. DOINGINACT prevents us from recursing in calls to vinactive.