From nobody Tue Apr 7 14:21:29 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EBCBA34028B for ; Fri, 3 Apr 2026 14:13:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775225597; cv=none; b=brX9Yppp7hiOPios1nC+6mbRneqFgG19FUXHfAvkhecn9rO70ZIZzLpd4wFi7EzTz7CcVXfoH0SdoD96NIYeUPMdBN20uH4V3uHGLNZCZTC3lVnrXEfP7NZ4OVI2EcvSvKBRuoOLDs/7CjG0GfyN8XS4ABS54KeRBK4QVf1vApQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775225597; c=relaxed/simple; bh=pKR+okoCybqgnvAwwN0fmXR4Q8RrZm0wNhzQW0p4g3M=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=aygU6Vuz4wrkm9znbsUZVYXtpT3ftvul8n/umccq1SzdMuIgIYukBQEzWJQnJ7GSEpa5iQd4bBvRxYF9JCGTJvnPjbIvOrcnygLb+zzwEJgp60NOFwkHxM2A6JD3n/uRGd9K9inidECCHwcoBvY1sNB3UoaOxUYh2WANzMB03j8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Fw1vH9Wz; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=R6LGROoX; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Fw1vH9Wz"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="R6LGROoX" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1775225594; h=from:from: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=F2OXmkPnk3xdLi6S85WCOSMj2pCVYR8dHaWwnDoveRE=; b=Fw1vH9WzkLV0kB9htYYwuju/QCwYnEvPzffJOimRcNAeznXBhISWp+VYz9UlnCbOj11r0g Sqs5tI4LVCLw+sGc9XJ8FxhiYs4fdyPV2PwTJMJ6XXFSyxJufboYPSqi56NtSr4D/Ni9YY sZXM9JUmkiloJ9jwD0B1eDZn+mnJECE= Received: from mail-qv1-f71.google.com (mail-qv1-f71.google.com [209.85.219.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-416-XEBXcEpUNIK6TgYZbOy3dw-1; Fri, 03 Apr 2026 10:13:13 -0400 X-MC-Unique: XEBXcEpUNIK6TgYZbOy3dw-1 X-Mimecast-MFC-AGG-ID: XEBXcEpUNIK6TgYZbOy3dw_1775225592 Received: by mail-qv1-f71.google.com with SMTP id 6a1803df08f44-8a1f96bf221so74041666d6.3 for ; Fri, 03 Apr 2026 07:13:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1775225592; x=1775830392; darn=vger.kernel.org; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:from:to:cc:subject:date:message-id :reply-to; bh=F2OXmkPnk3xdLi6S85WCOSMj2pCVYR8dHaWwnDoveRE=; b=R6LGROoXW6ZwzHBKEiwXnn2uA8/HHGcRPAdjqne9MXGYk5BbntXhXWE3b62fgUFQVm gLTmWnWOZmjM32R5vFYbvXZSg2WVIp7EtqvINWEZq78j9OjwdyQ/btUwC+m2eP0kJQgF zP1Msj88PxEGhGd3P6Qga5tXg3/XeFpR+ReZrnrQ54rOQva73wCeCSlKgRhuaAG10w1E qQKnUVkbOsvhDrMnjpi0A4Jndr6GCkyKAwXLEsTOfHMEK88dY7+5gtvDXqypoVbuTVDj vy9Dcj/lkIwQqH6c0DIMiNTaLbYt+MpXz/N3QxHUJE0tvCAQiOuRIfVhjw/6YunUcxWl o/Lw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775225592; x=1775830392; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:x-gm-gg:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=F2OXmkPnk3xdLi6S85WCOSMj2pCVYR8dHaWwnDoveRE=; b=Cqahi4TLR/F/9Vpf804k0aENdEUZ1tYr/7TCfcRAp0TpC6dC1XzPXt2kccqeI8P6Jj 56/DNcCq9csF98CSSLOrypj200qluMJuju0zcY9RfpomG4DergHTHr7AT/+TokleRKS1 t7BdJa5KLw9KUR9LZGYopiDJjeW3zsFlKb/ugl/9qCWFZ4EvgNxyIfBj+GFKjlPTR38N 3Wzno83YwItsV+yVSHyELGgCiJVhG+3zUYqLl9poI4A25IySlOA2H+yFVcAM2ob2VBHE PJ16Gog+xdyp2AoYSJSoVllKIiX/b92z9277A2k7RApZq4NRTQQKehEEBWpmoYBl9PYV sozA== X-Forwarded-Encrypted: i=1; AJvYcCXxY4ALtGHcMcMEW0fsOnZymN9BERWFjj1OALsDd/zCc1kNT/L4ANMHFFDI79UiORbWZPpTeiGV7vI2/3s=@vger.kernel.org X-Gm-Message-State: AOJu0YzH3vV2WaPKLg1vZJk/BEuGXJMtGlbuy+RP67OwtcmONh1AMkYF +Vk2i0kGvwhOlClIL3TSjV66rW7t1Bdr81NnCFjPP3w0LmXhP9n1viuYW85feGyOW/MiQSMe00G ztvOBBGsqC8L8wcD+6I946NVZGBd/UwW8kBRoiX5PtjLQsBse0zKSMxX3hVGDwp5q/w== X-Gm-Gg: AeBDietzpGIx51+l0495Bkb3xVB47myxezs93QJx5YnN30TdrX/EOfkqyTSTtJgwLiv VWYW4S/6Tocp1SmUrVjwBEi8E2qhIzCbegE9wLpW8Ut+guMibbkxRDl2UYgzkwUztxNjSxUlLbK HcL2rk/rXqPB8YNTye9nACoNfg4gKflB3pSM1owFv6i6WMKx2exEisq/WmZB8id1p84138yUkQx pyy4XuR78Bk1FOyT+gG4YqRkwzqmZXQKup21YKSJjXLueyWpvcbERvPzWU56gtkbsBw9x9TtVJ1 tBmCLCi7rdM/PBY6IWCIPHqE3WGwKvcMSvWv8UkLTdI9dTsikHetghJ2jVc5f+982xYy8/XSj60 Q2ufNbU2GPSuv592ff4fLXlKksSnxyDRYLvNUEO8gyj1HTcTP7L6G5gNnex0yKFQ= X-Received: by 2002:a05:6214:76d:b0:89f:123c:4d9c with SMTP id 6a1803df08f44-8a7025b7636mr47917256d6.18.1775225592246; Fri, 03 Apr 2026 07:13:12 -0700 (PDT) X-Received: by 2002:a05:6214:76d:b0:89f:123c:4d9c with SMTP id 6a1803df08f44-8a7025b7636mr47916446d6.18.1775225591562; Fri, 03 Apr 2026 07:13:11 -0700 (PDT) Received: from localhost (pool-100-17-19-56.bstnma.fios.verizon.net. [100.17.19.56]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-8a593330a98sm50147126d6.2.2026.04.03.07.13.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 Apr 2026 07:13:11 -0700 (PDT) From: Eric Chanudet Date: Fri, 03 Apr 2026 10:08:35 -0400 Subject: [PATCH RFC 1/2] mm/memcontrol: add page-level charge/uncharge functions 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="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260403-cgroup-dmem-memcg-double-charge-v1-1-c371d155de2a@redhat.com> References: <20260403-cgroup-dmem-memcg-double-charge-v1-0-c371d155de2a@redhat.com> In-Reply-To: <20260403-cgroup-dmem-memcg-double-charge-v1-0-c371d155de2a@redhat.com> To: Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , Andrew Morton , Maarten Lankhorst , Maxime Ripard , Natalie Vock , Tejun Heo , =?utf-8?q?Michal_Koutn=C3=BD?= Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, "T.J. Mercier" , =?utf-8?q?Christian_K=C3=B6nig?= , Maxime Ripard , Albert Esteve , Dave Airlie , Eric Chanudet X-Mailer: b4 0.14.2 Expose functions to charge/uncharge memcg with a number of pages instead of a folio. Signed-off-by: Eric Chanudet --- include/linux/memcontrol.h | 4 ++++ mm/memcontrol.c | 24 ++++++++++++++++++++++++ 2 files changed, 28 insertions(+) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 70b685a85bf4cd0e830c9c0253e4d48f75957fe4..32f03890f13e06551fc910515eb= 478597c1235d8 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -642,6 +642,8 @@ static inline bool mem_cgroup_below_min(struct mem_cgro= up *target, =20 int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t g= fp); =20 +int mem_cgroup_try_charge_pages(struct mem_cgroup *memcg, gfp_t gfp_mask, + unsigned int nr_pages); /** * mem_cgroup_charge - Charge a newly allocated folio to a cgroup. * @folio: Folio to charge. @@ -692,6 +694,8 @@ static inline void mem_cgroup_uncharge_folios(struct fo= lio_batch *folios) __mem_cgroup_uncharge_folios(folios); } =20 +void mem_cgroup_uncharge_pages(struct mem_cgroup *memcg, unsigned int nr_p= ages); + void mem_cgroup_replace_folio(struct folio *old, struct folio *new); void mem_cgroup_migrate(struct folio *old, struct folio *new); =20 diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 772bac21d15584ce495cba6ad2eebfa7f693677f..49ed069a2dafd5d26d77e6737df= fe7e64ba5118c 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4764,6 +4764,24 @@ int __mem_cgroup_charge(struct folio *folio, struct = mm_struct *mm, gfp_t gfp) return ret; } =20 +/** + * mem_cgroup_try_charge_pages - charge pages to a memory cgroup + * @memcg: memory cgroup to charge + * @gfp_mask: reclaim mode + * @nr_pages: number of pages to charge + * + * Try to charge @nr_pages to @memcg through try_charge_memcg. + * + * Returns 0 on success, an error code on failure. + */ +int mem_cgroup_try_charge_pages(struct mem_cgroup *memcg, gfp_t gfp_mask, + unsigned int nr_pages) +{ + return try_charge(memcg, gfp_mask, nr_pages); +} +EXPORT_SYMBOL_GPL(mem_cgroup_try_charge_pages); + + /** * mem_cgroup_charge_hugetlb - charge the memcg for a hugetlb folio * @folio: folio being charged @@ -4948,6 +4966,12 @@ void __mem_cgroup_uncharge_folios(struct folio_batch= *folios) uncharge_batch(&ug); } =20 +void mem_cgroup_uncharge_pages(struct mem_cgroup *memcg, unsigned int nr_p= ages) +{ + memcg_uncharge(memcg, nr_pages); +} +EXPORT_SYMBOL_GPL(mem_cgroup_uncharge_pages); + /** * mem_cgroup_replace_folio - Charge a folio's replacement. * @old: Currently circulating folio. --=20 2.52.0