From nobody Wed Oct 08 17:01:57 2025 X-Original-To: dev-commits-src-main@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 4chfS61FxTz6B5b2; Wed, 08 Oct 2025 17:01:58 +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 "R12" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4chfS60kckz3JYY; Wed, 08 Oct 2025 17:01:58 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1759942918; 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=5CTe+nRoDbYojLrHKylwt/Jd7Gj0vEVk+t+NtqUVSLY=; b=prRrexDfrmXe1BP0HBuhwiQopZ9n2STcX5EA7AmnIPN1ov/uFeyAh4z/P9USiI7wrNVa7m CgrHVB2q7M3DnDQu/tLc9JH9HHuSPP3tCGy0ufNH1auTWnqUX2PK2k1cGyg3h5b8MmkvKv KdfwkEn7UMJBxsa8ghDQRtlGGxtn5mAdoVKNedKC9cF5Ge/I1c0NtNUwReXzH9BmzAN7cR Do+Jo3sTkh5tE159Wnr6ogJFh32QHCbvsOZMN2P1L46+PiSEgUEoU83Nl0nufH1B8H6ssp HfgS6m65/Abv1aqAK/fDOOg7yyzQBZB1ZXgswcxyJoCHwVe+/A8vyuudys7n3w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1759942918; 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=5CTe+nRoDbYojLrHKylwt/Jd7Gj0vEVk+t+NtqUVSLY=; b=WLQ/N77nrmU1cda0346vzznligJq87Yz0cUXZ8zLeFn4+YYAmStpUXklbPgetI3KdLGI/8 qA+X9mAdQM6QfHmZtLW5lZ5LH+SKr/d92LBBJY/WZwhjZbA9NugHHlegdSH7pv5YQChnEW tBmbsxQfX3AN9FnfCjd/kixO/qaNgMsxFmGUPq6b34v+ne7Mq+KnGQV4aeoFrbDDiew4Pr m4jogux7gaQUYsreh60wF4DKRDSVPQ2gxFFUfcPr/QYHrveu4hK+1oMBPnoLMxxEFG9eDs IP+CSqCR+cclWORuwf6IFeLedmBL1T7jYpQvg5njEwp9DYtYxJ0MAFBC1Ak9ig== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1759942918; a=rsa-sha256; cv=none; b=MuVE2vGZQYZCe80AZ5568O+1YNDKaY5aXc/d6TuMI9SYomeNWHvokx7yN+J1sLfP5dCLLg ubWkrl9705aiT+XjO3bwy5CgIqAd/yw/xSkzHJBAVMcdPt9sw7CgF3q9RFSOICkMhbOUkW KVhQU7zhvgsD8oPod1ly2+2SvzXUxMV+7qD6e1oy9jO2ElXZKiPnVoGJNyrG4Pk4ZNrlJV xgkiPJHN9Llp6HJrytgXvcprPzAPQD2y2/PfMyL5SgaKL8ipz4kmmqgGE3d7yWAj+zdaUS 8oGpYijZT3j0BrxDh7juSW7pFe1D38CEhbzsx7dmUqoTQUsM99wn0ntJjqiQkQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none 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 4chfS56tr6zgTg; Wed, 08 Oct 2025 17:01:57 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.18.1/8.18.1) with ESMTP id 598H1vSM064654; Wed, 8 Oct 2025 17:01:57 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 598H1vl1064651; Wed, 8 Oct 2025 17:01:57 GMT (envelope-from git) Date: Wed, 8 Oct 2025 17:01:57 GMT Message-Id: <202510081701.598H1vl1064651@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Olivier Certner Subject: git: 781802df7a2b - main - uma_core: Rely on domainset iterator to wait on M_WAITOK List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-main@freebsd.org Sender: owner-dev-commits-src-main@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/main X-Git-Reftype: branch X-Git-Commit: 781802df7a2bfe224ef17596d56cf83c49517655 Auto-Submitted: auto-generated The branch main has been updated by olce: URL: https://cgit.FreeBSD.org/src/commit/?id=781802df7a2bfe224ef17596d56cf83c49517655 commit 781802df7a2bfe224ef17596d56cf83c49517655 Author: Olivier Certner AuthorDate: 2025-09-08 17:37:35 +0000 Commit: Olivier Certner CommitDate: 2025-10-08 16:59:47 +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 --- 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__); } } }