From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2FA4CCD4855 for ; Tue, 12 May 2026 09:01:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9AA0D6B008C; Tue, 12 May 2026 05:01:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 95ADC6B0093; Tue, 12 May 2026 05:01:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8707E6B0095; Tue, 12 May 2026 05:01:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 755A56B008C for ; Tue, 12 May 2026 05:01:13 -0400 (EDT) Received: from smtpin17.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 22428160411 for ; Tue, 12 May 2026 09:01:13 +0000 (UTC) X-FDA: 84758173626.17.09C57B5 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) by imf29.hostedemail.com (Postfix) with ESMTP id E54DD120009 for ; Tue, 12 May 2026 09:01:10 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=bFndAirc; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b="f4EaLA/9"; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=WxcQy8D1; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=+aFIXJOf; spf=pass (imf29.hostedemail.com: domain of osalvador@suse.de designates 195.135.223.130 as permitted sender) smtp.mailfrom=osalvador@suse.de; dmarc=pass (policy=none) header.from=suse.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1778576471; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=5/z7ZTk/tQ8MkYUf+nJ2M5F66Apw+zBhv2IgQMZTmJY=; b=w1//WksgWk41BJg8PojSDNFWRIyWAUlzT7iTreJlvl20/zRu45hTxLws0zQYk4XZnyGEAc LdgxKmO+++5VVtbu9mKVMCURprggyzE49jIaIQKxbYp+brida+jXbLsF3sItG2/LUQ7H6E ALNb39iyy9V4a8bkYbcSVw5M2WsiqoE= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=bFndAirc; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b="f4EaLA/9"; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=WxcQy8D1; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=+aFIXJOf; spf=pass (imf29.hostedemail.com: domain of osalvador@suse.de designates 195.135.223.130 as permitted sender) smtp.mailfrom=osalvador@suse.de; dmarc=pass (policy=none) header.from=suse.de ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1778576471; a=rsa-sha256; cv=none; b=vrBRwl5fwDl2yRfYZv9zRkJsbhoQF4RQXuy7lR3Xy/gcBewYGkiSNrC5spJ8COiGDx1p4+ bTOZ+BElq5yWMg8K8J2IO4PXl16v8y2POtHd98KYHImrxLBcVD0V0ZD93yNHEqTTYKEFIW dbxD+RQW1fkJIJJCSVJTfFw+bm1CZaA= Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (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) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 846806C086; Tue, 12 May 2026 09:01:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1778576465; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=5/z7ZTk/tQ8MkYUf+nJ2M5F66Apw+zBhv2IgQMZTmJY=; b=bFndAircj6+1Iv4cxlSlzbaapEK5J/tU+FELrckYs0QFPl7KAV1V54ZgvYP5IBYYN53EtF Qk6hZvpoGl8jA998BnN15JuYhGBumMLysmKfCr81OehqGmFq4EObaECqi7R45EMYXBFjqo p5q/BLk5f4gC7o+YZfb11BVKGe9pLGI= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1778576465; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=5/z7ZTk/tQ8MkYUf+nJ2M5F66Apw+zBhv2IgQMZTmJY=; b=f4EaLA/9+meXhx5VCjOiTGPPfyXS89pL6iIJdOhfhy6h1hw/5Ic8F0tBHKGenlVsdUU7pg TXCdLtOKNizK9dAg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1778576460; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=5/z7ZTk/tQ8MkYUf+nJ2M5F66Apw+zBhv2IgQMZTmJY=; b=WxcQy8D1XEtGhDGDeVWdTTkVAzO/AN6iyMxRRs1kblvvn69iGGmTj5g9qNjhDDiD1vBI8H fz7jew0aXEKqgF0a5dI5KQxaHuh/RrWFPGw4C4B+FHuOlOTptMGfA5UQ6+ZqRjNkyljlEu cOazouVeFZ2m655gIoZkInOJ0wsx3Hc= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1778576460; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=5/z7ZTk/tQ8MkYUf+nJ2M5F66Apw+zBhv2IgQMZTmJY=; b=+aFIXJOfEyUf1rLxTRzulY7j0rGUN0PNYQnqpcaFbhutZtHtcxfb+M5wTutiEQzHUfYf+c U33XZ4FvOcUES+DQ== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (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) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 74BD9593A9; Tue, 12 May 2026 09:00:59 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id KLVdGkvsAmrfHAAAD6G6ig (envelope-from ); Tue, 12 May 2026 09:00:59 +0000 Date: Tue, 12 May 2026 11:00:53 +0200 From: Oscar Salvador To: ackerleytng@google.com Cc: Muchun Song , David Hildenbrand , Andrew Morton , fvdl@google.com, jiaqiyan@google.com, joshua.hahnjy@gmail.com, jthoughton@google.com, mhocko@kernel.org, michael.roth@amd.com, pasha.tatashin@soleen.com, pbonzini@redhat.com, peterx@redhat.com, pratyush@kernel.org, rick.p.edgecombe@intel.com, rientjes@google.com, roman.gushchin@linux.dev, seanjc@google.com, shakeel.butt@linux.dev, shivankg@amd.com, vannapurve@google.com, yan.y.zhao@intel.com, Dan Williams , Jason Gunthorpe , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/6] mm: hugetlb: Consolidate interpretation of gbl_chg within alloc_hugetlb_folio() Message-ID: References: <20260506-hugetlb-open-up-v2-0-826a0c5f28fc@google.com> <20260506-hugetlb-open-up-v2-1-826a0c5f28fc@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260506-hugetlb-open-up-v2-1-826a0c5f28fc@google.com> X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: E54DD120009 X-Rspam-User: X-Stat-Signature: ot5c5xk83up5gg56grw4guj1brau6586 X-HE-Tag: 1778576470-711034 X-HE-Meta: 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 mNpkWL26 jjJIxPgyTXE6Qg/CRZ1/OO6yi76P8KjOPGct+d1I2xF9cHJdAMOEdKUYwlnwC2CVwsLCJ68O5utJ8tSW83BUdr1rw4Mgk5FYHTRNBXBGLsne38JH1jc13hyQ3CgIAIQFN79Q5RjohhHixdNDeIUpYCjZkNpzDfaDQ/vx2wRgsBu2X9SVg1RFvVc9mPSsUOj4CVXkWB6jmLoHFuOThyKzcHr2uZeoFIa45lmMnwTZXAITcY9Qk3UEVwkmUH4hXWd+fWn7lZi86xB7E/FLEqGJr+vH7ToQeLTDSoEfxKMmJbF0CSQ6iN2kN2anV7CYOLvXCZrpTrzkOWGPl2hVt0HeuQwAxluH+yDNLsf0mNozKMYimA0A9QS3BhnCEaUf2nq5ik5+MDgK6fkobohroeFEG7RQnG80UNhRoaGCWRnaIBc+SreISzx1PFuZOh4jQpYc2/6WB Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, May 06, 2026 at 08:54:37AM -0700, Ackerley Tng via B4 Relay wrote: > From: Ackerley Tng > > The dequeue_hugetlb_folio_vma() function currently handles the gbl_chg > parameter to determine if a folio can be dequeued based on global page > availability. This leaks reservation-specific logic into the dequeueing > path. > > Relocate this logic to alloc_hugetlb_folio() so that > dequeue_hugetlb_folio_vma() focuses solely on selecting and dequeuing a > folio. In alloc_hugetlb_folio(), only attempt to dequeue a folio if a > reservation exists (gbl_chg == 0) or if there are available huge pages in > the global pool. > > No functional change intended. > > Signed-off-by: Ackerley Tng > Reviewed-by: James Houghton Acked-by: Oscar Salvador I am ok with this but: > --- > mm/hugetlb.c | 24 +++++++++--------------- > 1 file changed, 9 insertions(+), 15 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index f24bf49be047e..8be246b4e6134 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c ... > @@ -2939,12 +2929,16 @@ struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma, > goto out_uncharge_cgroup_reservation; > > spin_lock_irq(&hugetlb_lock); > + > /* > - * glb_chg is passed to indicate whether or not a page must be taken > - * from the global free pool (global change). gbl_chg == 0 indicates > - * a reservation exists for the allocation. > + * gbl_chg == 0 indicates a reservation exists for the allocation - so > + * try dequeuing a page. If there are available_huge_pages(), try using > + * them! This comment is a bit obfuscated. I miss "in case there is no reservation, check whether we have available pages in the pool to satisfy the request" or something like that. -- Oscar Salvador SUSE Labs