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 picard.linux.it (picard.linux.it [213.254.12.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 384D6C433F5 for ; Fri, 10 Dec 2021 10:39:39 +0000 (UTC) Received: from picard.linux.it (localhost [IPv6:::1]) by picard.linux.it (Postfix) with ESMTP id AF6F63C8264 for ; Fri, 10 Dec 2021 11:39:36 +0100 (CET) Received: from in-2.smtp.seeweb.it (in-2.smtp.seeweb.it [217.194.8.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by picard.linux.it (Postfix) with ESMTPS id 3DC383C1D2E for ; Fri, 10 Dec 2021 11:39:26 +0100 (CET) Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by in-2.smtp.seeweb.it (Postfix) with ESMTPS id 46638600803 for ; Fri, 10 Dec 2021 11:39:25 +0100 (CET) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 376E11F3A0; Fri, 10 Dec 2021 10:39:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1639132765; 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=qnwD3NsePZviFFYypWGtnOanaZND5WHOuDeQ1ojqwUs=; b=U7m077A2GhZ/A/71bXLK5P61iZ7o5f0ReR36x3z1ZzJBgulrDnYMxZ3qPsFazbexSo3emS 09lVfF1BAEAkzdUcdx2PEdzqbURasKctlgn0tQDIYWaidv2CY9PSb9/0jUpIsNOvhbhOOb Xxvz+HLw6L5PS3xChLbg7jcLCnpWzAA= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1639132765; 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=qnwD3NsePZviFFYypWGtnOanaZND5WHOuDeQ1ojqwUs=; b=PiKiYgfZlMWCmsoF2HM7eIdozJkM2yLbBUUKVtfKncjvXCkpA/n4jHBeNCq2ogYthhwpn1 2mfisHDXdsgBsoBA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 14D4A13C1D; Fri, 10 Dec 2021 10:39:25 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id WwsZA10us2GDVQAAMHmgww (envelope-from ); Fri, 10 Dec 2021 10:39:25 +0000 Date: Fri, 10 Dec 2021 11:40:45 +0100 From: Cyril Hrubis To: Luke Nowakowski-Krijger Message-ID: References: <87pmqfcp4j.fsf@suse.de> <87ilw2ccgv.fsf@suse.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Virus-Scanned: clamav-milter 0.102.4 at in-2.smtp.seeweb.it X-Virus-Status: Clean Subject: Re: [LTP] [PATCH 1/4] controllers/memcg: update stress test to work under cgroup2 X-BeenThere: ltp@lists.linux.it X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Test Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: LTP List Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-bounces+ltp=archiver.kernel.org@lists.linux.it Sender: "ltp" Hi! > Yes, we would have to remember what we mounted. I think the part I am most > curious about is how we would generate that state i.e what we mounted, > because the Cgroup library does not expose any of this as far as I'm aware. > > If we want to use the tst_cgroup C lib to cleanup as well we would have to > find a way to reintroduce test state to the lib that we are losing between > calls of the utility, which the only way I could think of is introducing a > way to export and import test state within the lib. e.g. > tst_cgroup_print_test_state() tst_cgroup_load_test_state(), which doesn't > feel good as it exposes some of the nice API you have going on. This is the > easiest way to tell if we are mounting things because we can just print > what we mounted, what the test dir of the test is, and reload that state. > This could have further applications to not just this scenario but also to > scenarios where if a test dies its state can be reloaded, etc, almost in a > checkpoint way. Not saying its common but adds some flexibility to the API > and I could see it having applications outside of this utility. > > Alternatively we could inspect what we created and generate state that way, > i.e. make a call to tst_cgroup_require() and see if new things were > mounted. Then we would have to manually be freeing things. I don't like > this approach because it goes against the whole point of this which was > code reuse. But the cleanup of things isnt the most difficult part so it > wouldn't be the biggest deal to redo the logic. > > Yes, sounds good. > > > > > Let me know what you think. I wouldn't want to add anything huge to the API > without your blessing :) Wouldn't it be easier to rewrite these test to the C then? I think that error handling in shell CGroup tests would always be more difficuilt than in C and given that we have a nice library for C it actually sounds like a better solution. -- Cyril Hrubis chrubis@suse.cz -- Mailing list info: https://lists.linux.it/listinfo/ltp