From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH] PM / suspend: measure the time of filesystem syncing Date: Wed, 6 Feb 2019 15:53:22 +0100 Message-ID: <20190206145322.GA31815@amd> References: <20190203052007.27392-1-harry.pan@intel.com> <20190206144257.21464-1-harry.pan@intel.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="fdj2RfSjLxBAspz7" Return-path: Content-Disposition: inline In-Reply-To: <20190206144257.21464-1-harry.pan@intel.com> Sender: linux-kernel-owner@vger.kernel.org To: Harry Pan Cc: LKML , gs0622@gmail.com, rjw@rjwysocki.net, len.brown@intel.com, linux-pm@vger.kernel.org List-Id: linux-pm@vger.kernel.org --fdj2RfSjLxBAspz7 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed 2019-02-06 22:42:57, Harry Pan wrote: > This patch gives the reader an intuitive metric of the time cost by > the kernel issuing a filesystem sync during suspend; although developer > can guess by the timestamp of next log or enable the ftrace power event > for manual calculation, this manner is easier to read and benefits the > automatic script. >=20 > v2: simplify the variables, apply the simplest form of ktime API. >=20 > Signed-off-by: Harry Pan NAK. Pavel =09 > --- > kernel/power/suspend.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) >=20 > diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c > index 0bd595a0b610..87c0073f0c9d 100644 > --- a/kernel/power/suspend.c > +++ b/kernel/power/suspend.c > @@ -550,6 +550,8 @@ static void suspend_finish(void) > static int enter_state(suspend_state_t state) > { > int error; > + ktime_t start; > + unsigned int elapsed_msecs; > =20 > trace_suspend_resume(TPS("suspend_enter"), state, true); > if (state =3D=3D PM_SUSPEND_TO_IDLE) { > @@ -570,9 +572,12 @@ static int enter_state(suspend_state_t state) > =20 > #ifndef CONFIG_SUSPEND_SKIP_SYNC > trace_suspend_resume(TPS("sync_filesystems"), 0, true); > + start =3D ktime_get(); > pr_info("Syncing filesystems ... "); > ksys_sync(); > - pr_cont("done.\n"); > + elapsed_msecs =3D ktime_to_ms(ktime_sub(ktime_get(), start)); > + pr_cont("(elapsed %d.%03d seconds) done.\n", elapsed_msecs / 1000, > + elapsed_msecs % 1000); > trace_suspend_resume(TPS("sync_filesystems"), 0, false); > #endif > =20 --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --fdj2RfSjLxBAspz7 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlxa9OIACgkQMOfwapXb+vK41wCfUiP4kyXwCFDr3IyBSoRpYFAs qTYAn32HBKY2Z4CbT1r7Yjw5qII8hYAc =meE1 -----END PGP SIGNATURE----- --fdj2RfSjLxBAspz7--