From nobody Tue Jan 6 13:34:23 2026 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 4dlsb33VkMz6Ndm7 for ; Tue, 06 Jan 2026 13:34:23 +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 "R13" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4dlsb319GYz3StS for ; Tue, 06 Jan 2026 13:34:23 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1767706463; 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=ej978+sgn1mHMNf86AXeEZhr8fihVuN3ODvzZ7P2Q8c=; b=XTzCigWbKBaHtgwtrNBgVs1xMsrAgBF/L3nhUbLlXSAvBhm/G1HHuVapce6sxvInnd8Hbx hs0X0ftIhTgijZ87N23QffshEph8FPlKH4pObn5xbFUtyej83woamHdvZr5npWTV4ztXy9 N6U3QThFpq6SL44DK+Gn2CkRfL3C6O85EEhY83zylea00uZ2Mvf1uuljffIk18zywUPtsX tGAZr2T26ZOC0eeF3eTDXcmsl7CvdqLLx1IlOAyKHPsNcbETebS5SJHWR3zyeqs5M/EPd0 wT5STnX+kI83qTZ/OuRsGIkTEDAmMGKcQJ3nAZtezUrzHCTACvUTFhGd4u5QEQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1767706463; 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=ej978+sgn1mHMNf86AXeEZhr8fihVuN3ODvzZ7P2Q8c=; b=sgmD4IIFPTKIUcN4/Icu+EvwP8nylkXb4ZeFj6Zz9kwnTWWGfXrMHDgF/CXfuH4xFDUvaq CvP6Qxa7QboM6gTEFwhUBha4WJ02VKLTjr74oO3qt3wHhgHp11o4yxX1AtvOIZQyWmn1Lg C3cGOjTsAgRWL2GDUMzIj9p7t5wdn0fNZEVBZ19ApEiW++BAe1t+nWhy2AuFS4EbnKgkpW fZFNsaaVcmgh5aqQDzWPMrSkTr52+K9JPdtbPAGYH5b8x/MDKofzd/qpVczKM79CjTl+nP Ex25us4FbUrtK/E9fTy7ULHCH11zWbFmiZPxByj+tuhzOPloVGFPQJ4gaQmoQw== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1767706463; a=rsa-sha256; cv=none; b=MqFCJch7c0vDwe36ImXOaVMDii0zmqaUBzVoN1I8KMZyfdEDu+HCs9IVUNCeVG8lCOk0XR RTZLo6CUOEaeHOgHjl59AP6hwUVkHNsmt2iAYpTJ1IKJxsTA/jhoiU763MxLgwLuZFIs+O J++i8f0b2PwpoDyXr9HO1cEsT3XpBoMG6F6b8wvifrNhv3aFBo49+EViGMQSdMzN343634 XBYaOeRtyMAQEVDeSNLtYO4DxBKlNQ7cvKxydZS5kMp9QJtpSSwgEQz6GUd1fQ8EuOhGm0 Oc38eCII5MUugXFLfXlfcs8RHQ4SoBa7+EbgfSTvNJ8GoFWGjP3F7Wyrr761Dg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4dlsb303vMz17lK for ; Tue, 06 Jan 2026 13:34:23 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 3e660 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Tue, 06 Jan 2026 13:34:23 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Olivier Certner Subject: git: 66f43dae8c64 - stable/15 - uma_core: Rely on domainset iterator to wait on M_WAITOK 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: X-BeenThere: dev-commits-src-all@freebsd.org Sender: owner-dev-commits-src-all@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: olce X-Git-Repository: src X-Git-Refname: refs/heads/stable/15 X-Git-Reftype: branch X-Git-Commit: 66f43dae8c641ceea11eabe4c9c4ffb56dd2ac98 Auto-Submitted: auto-generated Date: Tue, 06 Jan 2026 13:34:23 +0000 Message-Id: <695d0f5f.3e660.10fdbe1f@gitrepo.freebsd.org> The branch stable/15 has been updated by olce: URL: https://cgit.FreeBSD.org/src/commit/?id=66f43dae8c641ceea11eabe4c9c4ffb56dd2ac98 commit 66f43dae8c641ceea11eabe4c9c4ffb56dd2ac98 Author: Olivier Certner AuthorDate: 2025-09-08 17:37:35 +0000 Commit: Olivier Certner CommitDate: 2026-01-06 13:33:23 +0000 uma_core: Rely on domainset iterator to wait on M_WAITOK Commit 8b987a77691d ("Use per-domain keg locks.") removed the need to lock the keg entirely, replacing it with per-domain keg locks. In particular, it removed the need to hold a lock over waiting for a domain to grow free memory. Simplify the code of keg_fetch_slab() and uma_prealloc() by removing the M_WAITOK -> M_NOWAIT downgrade and the local call to vm_wait_doms() (which used to necessitate temporary dropping the keg lock) which the iterator machinery already handles on M_WAITOK (and compatibly with vm_domainset_iter_ignore() at that, although that does not matter now). Reviewed by: bnovkov, markj Tested by: bnovkov MFC after: 3 days Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D52441 (cherry picked from commit 781802df7a2bfe224ef17596d56cf83c49517655) --- sys/vm/uma_core.c | 22 ++++++---------------- 1 file changed, 6 insertions(+), 16 deletions(-) diff --git a/sys/vm/uma_core.c b/sys/vm/uma_core.c index 679b2e20e88b..b80b5cc781f7 100644 --- a/sys/vm/uma_core.c +++ b/sys/vm/uma_core.c @@ -4009,21 +4009,15 @@ restart: /* * Use the keg's policy if upper layers haven't already specified a * domain (as happens with first-touch zones). - * - * To avoid races we run the iterator with the keg lock held, but that - * means that we cannot allow the vm_domainset layer to sleep. Thus, - * clear M_WAITOK and handle low memory conditions locally. */ rr = rdomain == UMA_ANYDOMAIN; + aflags = flags; if (rr) { - aflags = (flags & ~M_WAITOK) | M_NOWAIT; if (vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain, &aflags) != 0) return (NULL); - } else { - aflags = flags; + } else domain = rdomain; - } for (;;) { slab = keg_fetch_free_slab(keg, domain, rr, flags); @@ -4053,13 +4047,8 @@ restart: if ((flags & M_WAITOK) == 0) break; vm_wait_domain(domain); - } else if (vm_domainset_iter_policy(&di, &domain) != 0) { - if ((flags & M_WAITOK) != 0) { - vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask, 0); - goto restart; - } + } else if (vm_domainset_iter_policy(&di, &domain) != 0) break; - } } /* @@ -5245,7 +5234,7 @@ uma_prealloc(uma_zone_t zone, int items) KEG_GET(zone, keg); slabs = howmany(items, keg->uk_ipers); while (slabs-- > 0) { - aflags = M_NOWAIT; + aflags = M_WAITOK; if (vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain, &aflags) != 0) panic("%s: Domainset is empty", __func__); @@ -5266,7 +5255,8 @@ uma_prealloc(uma_zone_t zone, int items) break; } if (vm_domainset_iter_policy(&di, &domain) != 0) - vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask, 0); + panic("%s: Cannot allocate from any domain", + __func__); } } }