From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f42.google.com (mail-ej1-f42.google.com [209.85.218.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 612A3157472 for ; Tue, 19 Nov 2024 08:29:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.42 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732004960; cv=none; b=EAJTce5yE4MhaEH1fTa61a7A0vwzDvm0G+viV0FAa+9TZGe89q7ZTiepfa3rx5iV6yEXMRMoANbNPUdoPNoiYwm5zrZSHraOg55rbl2lLZkq4C+RlqVIohA6w3zZPvCDSHVKblzDwZ2SIX1DiNNELpfxgUarT46ep9cfevyBnaQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732004960; c=relaxed/simple; bh=bJDNNakkOymO9UdeCGUCR1wRhNYK1cwKNsqVhZJe8ug=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=uFTlmHEzWccJ6ofG8LSqxtqCyfbU+upbHCkOGkpPTpWHdqMYlrxd4P6VV09aC1B96zNrs3ybNi+W8/jy4QAr7slFRAYD+yIhHv4ys5p0e+9c2Lt1F+L+youWQ9W6A/xjihFEHpTxnTAxYSGpFWBUadq4MW/jssrgWv5FPLQFETE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b=Da4alwdR; arc=none smtp.client-ip=209.85.218.42 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b="Da4alwdR" Received: by mail-ej1-f42.google.com with SMTP id a640c23a62f3a-aa4d257eb68so28817466b.0 for ; Tue, 19 Nov 2024 00:29:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1732004957; x=1732609757; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=5jH4xv+sR4Al/gOR3OXvEI7SwC+hrXa/pJ8uLUM/+9U=; b=Da4alwdRhs/cq/tWnxPCOytcmmskj3O0QqbjaxrERQXO3Qr2a7i39eBXgjtAZal4nc QlQYoN/qXf56pzLSuRU2+I6p0jJFXmreqlKW+JoObSC8LCQwNQLSPo9EleGg8uyUzf7+ HZXgWbCPHUTvUM0dLcGCzCySGhanDg6mI/ifZtfaLbiYTyIvRDQyaNnxIHvsFh4ILD// JhAPbiEwb1WXm2h4ln5YtFmFfUFE+ZGgIlftdiFeIRvx9TQNoHAgujc4VM2Ltn0JpqrY 3amjLNy9H5ZyBGusfosPiKoxaR+0rJSCbC57aQGJkMNxSD12w4vb5x20NcXy9IfUxlT1 HIEg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1732004957; x=1732609757; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=5jH4xv+sR4Al/gOR3OXvEI7SwC+hrXa/pJ8uLUM/+9U=; b=cgwBrUXDo8EC1nbE+L+z4OtntWjuthA0MlWyGOdYAPqBEanJpQiHzqIXBa/vgzo6cn EgFhG2RCAUd0tsDU+bNAZHxF3nzl5e1zfAhTaUAg2yZs8pVnwDS6YWrtSU99MWcoNAJQ M8L1Fq1R6PgmiiPd5anl2THWsiauoqM8HgCxOZqQF52I/WtZvPO4BTL3j1GNcQdZzggq y2iqrlCoLrUOLBArOpNPIQpKe+DRD7lfABjG1UcaNjU4M7OZwdqnBS3EANdBcMt3wI1q yvO/gegjeSyNJpNpT3aoKdrqkYWYDKxORYwU2IT05Cb/NNPjEWJEVtr753fyTQkuthbA bBlw== X-Forwarded-Encrypted: i=1; AJvYcCUSkZQKD+I6Hu6Nn4FDrGU91ovzSsSjyL5NCi94Mu89kCDtZOgCQhHlJ3GTKZWUHFTvnsw78IbCNd0nZ7o=@vger.kernel.org X-Gm-Message-State: AOJu0Yz8br5hfLyJhTRRsWTShOG01+Vzq9YTeD8TtM8yG64lmGY6PoGY Mk59gwtpT7L+8mIDq42rFvLCuTPbMfDXRvPF3Ra1dxFXcUfPWVhGjWO/TvVSj6k= X-Google-Smtp-Source: AGHT+IEaZYns8YIqU8fVZizD6+A1wmyvYG60rg1tB1S9LYpkKleiNedOiGTxf1SR/nyQ4V3LKUmHkA== X-Received: by 2002:a17:907:7f0e:b0:aa2:be2:f1d1 with SMTP id a640c23a62f3a-aa4c7e17d55mr213141166b.10.1732004956734; Tue, 19 Nov 2024 00:29:16 -0800 (PST) Received: from localhost (109-81-88-120.rct.o2.cz. [109.81.88.120]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-aa20e046afdsm622185266b.163.2024.11.19.00.29.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 Nov 2024 00:29:16 -0800 (PST) Date: Tue, 19 Nov 2024 09:29:15 +0100 From: Michal Hocko To: Pavel Tikhomirov Cc: Linux Memory Management List , lkml , Andrew Morton Subject: Re: Question about vmalloc(GFP_NOFS) Message-ID: References: <112f93f3-455a-4b89-94c9-d12844d972ef@virtuozzo.com> <377a6aef-46a7-4492-a44f-b2a46869a9d0@virtuozzo.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <377a6aef-46a7-4492-a44f-b2a46869a9d0@virtuozzo.com> On Tue 19-11-24 15:24:03, Pavel Tikhomirov wrote: [...] > In commit 451769ebb7e79 ("mm/vmalloc: alloc GFP_NO{FS,IO} for vmalloc") we > add implicit memalloc_noXX_save/memalloc_noXX_restore at this code path: > > +->kvmalloc > +-> ... > +-> __kvmalloc_node_noprof > +-> __vmalloc_node_range_noprof > +-> __vmalloc_area_node > > So kvmalloc should be safe now with GFP_NOIO. Correct. > Should we correct the documentation? Yes, please. I think it would be useful to explicitly name the above commit because pre 5.17 kernels or those who haven't backported it are still in same position and that could get dangerous if they try to backport [k]vmalloc GFP_NOFS patches. Thanks! -- Michal Hocko SUSE Labs