linux-kernel - Re: [PATCH 2/3] tpm: reduce poll sleep time between send() and recv() in tpm

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Message-ID: <20180305180144.GE5791@linux.intel.com>
Date:   Mon, 5 Mar 2018 20:01:44 +0200
From:   Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
To:     Nayna Jain <nayna@...ux.vnet.ibm.com>
Cc:     linux-integrity@...r.kernel.org, zohar@...ux.vnet.ibm.com,
        linux-security-module@...r.kernel.org,
        linux-kernel@...r.kernel.org, peterhuewe@....de,
        tpmdd@...horst.net, jgunthorpe@...idianresearch.com,
        patrickc@...ibm.com
Subject: Re: [PATCH 2/3] tpm: reduce poll sleep time between send() and
 recv() in tpm_transmit()

On Mon, Mar 05, 2018 at 12:56:33PM +0200, Jarkko Sakkinen wrote:
> On Fri, Mar 02, 2018 at 12:26:35AM +0530, Nayna Jain wrote:
> > 
> > 
> > On 03/01/2018 02:52 PM, Jarkko Sakkinen wrote:
> > > On Wed, Feb 28, 2018 at 02:18:27PM -0500, Nayna Jain wrote:
> > > > In tpm_transmit, after send(), the code checks for status in a loop
> > > Maybe cutting hairs now but please just use the actual function name
> > > instead of send(). Just makes the commit log more useful asset.
> > Sure, will do.
> > > 
> > > > -		tpm_msleep(TPM_TIMEOUT);
> > > > +		tpm_msleep(TPM_TIMEOUT_POLL);
> > > What about just calling schedule()?
> > I'm not sure what you mean by "schedule()".  Are you suggesting instead of
> > using usleep_range(),  using something with an even finer grain construct?
> > 
> > Thanks & Regards,
> >      - Nayna
> 
> kernel/sched/core.c

The question I'm trying ask to is: is it better to sleep such a short
time or just ask scheduler to schedule something else after each
iteration?

/Jarkko