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protocol="application/pkcs7-signature"; micalg=sha-256; boundary="000000000000a1fb3b05ee05ff39" ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1669084415; a=rsa-sha256; cv=none; b=jZGWjIUOg7B6G3taX+jdHm9VpBl/EPzf1fz+0ZgSbVB9rV0iwSVLrBE9xz57cPFIMLm07r tNCG7+MHf6n42tIPoewWnkb8ib1S+1xZPCgLzgjncYB3OhW/dNrAOklEtDMFVYyYr1xB5W cqu7HLhHgh+Hol3S/24PZSXtpZd3a5w= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=nnw9tiM+; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf03.hostedemail.com: domain of davidgow@google.com designates 209.85.217.52 as permitted sender) smtp.mailfrom=davidgow@google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1669084415; 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=WsbC5F9CUadmgv+bFz7YKoSD2opZhbI0+eVqEq/3bdw=; b=sXsizjVV7miFcscDsf9Nrt8MmkzTMRC8yasNGk8Z1Rx482yBQcWimCDSbVrcvHnZ9MykgN SMOdn34XSkk1EQYHc3ffkSV4XHikF0iWlR9O5q8ItznrHaukT2sAvFHLKAo222uByGT71u s/y931s0pCqKeprdcOiInFihqRcRiMA= X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 28F272000B X-Rspam-User: Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=nnw9tiM+; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf03.hostedemail.com: domain of davidgow@google.com designates 209.85.217.52 as permitted sender) smtp.mailfrom=davidgow@google.com X-Stat-Signature: by6mk53tfdwdrrb8uajqj9jfq6xh1fm5 X-HE-Tag: 1669084414-377451 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000033, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: --000000000000a1fb3b05ee05ff39 Content-Type: text/plain; charset="UTF-8" On Tue, Nov 22, 2022 at 9:31 AM Daniel Latypov wrote: > > On Sat, Nov 19, 2022 at 12:13 AM David Gow wrote: > > > > KUnit does a few expensive things when enabled. This hasn't been a > > problem because KUnit was only enabled on test kernels, but with a few > > people enabling (but not _using_) KUnit on production systems, we need a > > runtime way of handling this. > > > > Provide a 'kunit_running' static key (defaulting to false), which allows > > us to hide any KUnit code behind a static branch. This should reduce the > > performance impact (on other code) of having KUnit enabled to a single > > NOP when no tests are running. > > > > Note that, while it looks unintuitive, tests always run entirely within > > __kunit_test_suites_init(), so it's safe to decrement the static key at > > the end of this function, rather than in __kunit_test_suites_exit(), > > which is only there to clean up results in debugfs. > > > > Signed-off-by: David Gow > > Reviewed-by: Daniel Latypov > > I didn't know anything about the static key support in the kernel > before this patch. > But from what I read and saw of other uses, this looks good to me. > > One small question/nit about how we declare the key below. > > > > > +/* Static key: true if any KUnit tests are currently running */ > > +extern struct static_key_false kunit_running; > > Is there any documented preference between this and > DECLARE_STATIC_KEY_FALSE(kunit_running); > ? > > I see 89 instances of this macro and 45 of `extern struct static_key_false`. > So I'd vote for the macro since it seems like the newer approach and > more common. > Yeah, there was no particular reason I put 'extern struct static_key_false'. I'll change it to DECLARE_STATIC_KEY_FALSE in v3. Cheers, -- David --000000000000a1fb3b05ee05ff39 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIIPnwYJKoZIhvcNAQcCoIIPkDCCD4wCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg ggz5MIIEtjCCA56gAwIBAgIQeAMYYHb81ngUVR0WyMTzqzANBgkqhkiG9w0BAQsFADBMMSAwHgYD VQQLExdHbG9iYWxTaWduIFJvb3QgQ0EgLSBSMzETMBEGA1UEChMKR2xvYmFsU2lnbjETMBEGA1UE AxMKR2xvYmFsU2lnbjAeFw0yMDA3MjgwMDAwMDBaFw0yOTAzMTgwMDAwMDBaMFQxCzAJBgNVBAYT AkJFMRkwFwYDVQQKExBHbG9iYWxTaWduIG52LXNhMSowKAYDVQQDEyFHbG9iYWxTaWduIEF0bGFz IFIzIFNNSU1FIENBIDIwMjAwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQCvLe9xPU9W dpiHLAvX7kFnaFZPuJLey7LYaMO8P/xSngB9IN73mVc7YiLov12Fekdtn5kL8PjmDBEvTYmWsuQS 6VBo3vdlqqXZ0M9eMkjcKqijrmDRleudEoPDzTumwQ18VB/3I+vbN039HIaRQ5x+NHGiPHVfk6Rx c6KAbYceyeqqfuJEcq23vhTdium/Bf5hHqYUhuJwnBQ+dAUcFndUKMJrth6lHeoifkbw2bv81zxJ 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