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[2620:137:e000::1:20]) by mx.google.com with ESMTP id x24-20020a63db58000000b0051358b5c88bsi6208497pgi.452.2023.03.28.22.50.48; Tue, 28 Mar 2023 22:51:00 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=bombadil.20210309 header.b=0s+ZsQtq; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229861AbjC2FcU (ORCPT + 99 others); Wed, 29 Mar 2023 01:32:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229765AbjC2FcF (ORCPT ); Wed, 29 Mar 2023 01:32:05 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 657F13C32; Tue, 28 Mar 2023 22:31:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=guyHag9qCqT02ycAP5gFYMiS5Z8MMs8Ps7B6B4e3yQk=; b=0s+ZsQtqvZrSA+dzaZX4im6LhE WyYiRJxXstb/bqMR3zp8lDLo3bPTmJaJEWSTCh06Aez4lV2UP5frUnAfsl7KhQGMydKgbO1lw7zhb 5jDrZkRjvFJfeHZVno0lB+v2bfAxpKG/fGbbO0mlzuPuljHB9FQjYJ/jVkpBdrh4YEiBJCnK3TUmn hiaTcVuownYisCxprFvcXdMGJps9Idj/5unt/K9XrpcpkHwN+cyMrQDW7fOwdPR91ENj/EqR2BYlX ZDIkrXjOcSqgk2+GqwuSjX7aetm38G9LIM3wHa+55pCtzqIALL7J0jkg4T34ZcZ7/7O5zQ66cDSM2 QzeATbHg==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1phOPW-00GgRb-2M; Wed, 29 Mar 2023 05:31:50 +0000 From: Luis Chamberlain To: david@redhat.com, patches@lists.linux.dev, linux-modules@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, pmladek@suse.com, petr.pavlu@suse.com, prarit@redhat.com, torvalds@linux-foundation.org, gregkh@linuxfoundation.org, rafael@kernel.org Cc: christophe.leroy@csgroup.eu, tglx@linutronix.de, peterz@infradead.org, song@kernel.org, rppt@kernel.org, willy@infradead.org, vbabka@suse.cz, mhocko@suse.com, dave.hansen@linux.intel.com, mcgrof@kernel.org Subject: [PATCH 4/7] sempahore: add a helper for a concurrency limiter Date: Tue, 28 Mar 2023 22:31:46 -0700 Message-Id: <20230329053149.3976378-5-mcgrof@kernel.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20230329053149.3976378-1-mcgrof@kernel.org> References: <20230329053149.3976378-1-mcgrof@kernel.org> MIME-Version: 1.0 Sender: Luis Chamberlain X-Spam-Status: No, score=-2.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1761680095745778940?= X-GMAIL-MSGID: =?utf-8?q?1761680095745778940?= While I looked at re-using the old kernel/kmod.c (now kernel/module/kmod.c) concurrency delimiter methodology for another place in the kernel Linus noted that this could be simply replaced with a sempahore [0]. So add that so we we don't re-invent the wheel and make it obvious to use. [0] https://lore.kernel.org/all/CAHk-=whkj6=wyi201JXkw9iT_eTUTsSx+Yb9d4OgmZFjDJA18g@mail.gmail.com/ Suggested-by: Linus Torvalds Signed-off-by: Luis Chamberlain Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Peter Zijlstra (Intel) --- include/linux/semaphore.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/include/linux/semaphore.h b/include/linux/semaphore.h index 6694d0019a68..2ecdffdb9814 100644 --- a/include/linux/semaphore.h +++ b/include/linux/semaphore.h @@ -28,6 +28,9 @@ struct semaphore { #define DEFINE_SEMAPHORE(name) \ struct semaphore name = __SEMAPHORE_INITIALIZER(name, 1) +#define CONCURRENCY_LIMITER(name, n) \ + struct semaphore name = __SEMAPHORE_INITIALIZER(name, n) + static inline void sema_init(struct semaphore *sem, int val) { static struct lock_class_key __key;