| Message ID | 1447215791-19429-1-git-send-email-yalin.wang2010@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Yalin, On Wed, Nov 11, 2015 at 9:53 AM, yalin wang <yalin.wang2010@gmail.com> wrote: > Use kmalloc instead of kzalloc, zero the memory is not needed. > why you want to do this? what problem you faces, and how this resolves the same? > Signed-off-by: yalin wang <yalin.wang2010@gmail.com> > --- > drivers/mmc/card/block.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c > index 23b6c8e..975cd3e 100644 > --- a/drivers/mmc/card/block.c > +++ b/drivers/mmc/card/block.c > @@ -365,7 +365,7 @@ static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user( > if (!idata->buf_bytes) > return idata; > > - idata->buf = kzalloc(idata->buf_bytes, GFP_KERNEL); > + idata->buf = kmalloc(idata->buf_bytes, GFP_KERNEL); > if (!idata->buf) { > err = -ENOMEM; > goto idata_err; > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
On 11/11/2015 12:02 PM, Alim Akhtar wrote: > Hi Yalin, > > On Wed, Nov 11, 2015 at 9:53 AM, yalin wang <yalin.wang2010@gmail.com> wrote: >> Use kmalloc instead of kzalloc, zero the memory is not needed. >> > why you want to do this? what problem you faces, and how this resolves the same? The patch fixes an inefficiency: explicitly zeroing memory that is then immediately overwritten 6 lines below is wasteful. Regards, Peter Hurley >> Signed-off-by: yalin wang <yalin.wang2010@gmail.com> >> --- >> drivers/mmc/card/block.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c >> index 23b6c8e..975cd3e 100644 >> --- a/drivers/mmc/card/block.c >> +++ b/drivers/mmc/card/block.c >> @@ -365,7 +365,7 @@ static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user( >> if (!idata->buf_bytes) >> return idata; >> >> - idata->buf = kzalloc(idata->buf_bytes, GFP_KERNEL); >> + idata->buf = kmalloc(idata->buf_bytes, GFP_KERNEL); >> if (!idata->buf) { >> err = -ENOMEM; >> goto idata_err; >> -- >> 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Nov 11, 2015 at 11:17 PM, Peter Hurley <peter@hurleysoftware.com> wrote: > On 11/11/2015 12:02 PM, Alim Akhtar wrote: >> Hi Yalin, >> >> On Wed, Nov 11, 2015 at 9:53 AM, yalin wang <yalin.wang2010@gmail.com> wrote: >>> Use kmalloc instead of kzalloc, zero the memory is not needed. >>> >> why you want to do this? what problem you faces, and how this resolves the same? > > The patch fixes an inefficiency: explicitly zeroing memory that is then > immediately overwritten 6 lines below is wasteful. It might fix previous kzalloc as well, though better not to do since it's error prone. > > Regards, > Peter Hurley > >>> Signed-off-by: yalin wang <yalin.wang2010@gmail.com> >>> --- >>> drivers/mmc/card/block.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c >>> index 23b6c8e..975cd3e 100644 >>> --- a/drivers/mmc/card/block.c >>> +++ b/drivers/mmc/card/block.c >>> @@ -365,7 +365,7 @@ static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user( >>> if (!idata->buf_bytes) >>> return idata; >>> >>> - idata->buf = kzalloc(idata->buf_bytes, GFP_KERNEL); >>> + idata->buf = kmalloc(idata->buf_bytes, GFP_KERNEL); >>> if (!idata->buf) { >>> err = -ENOMEM; >>> goto idata_err; >>> -- >>> 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
> On Nov 12, 2015, at 05:57, Andy Shevchenko <andy.shevchenko@gmail.com> wrote: > > On Wed, Nov 11, 2015 at 11:17 PM, Peter Hurley <peter@hurleysoftware.com> wrote: >> On 11/11/2015 12:02 PM, Alim Akhtar wrote: >>> Hi Yalin, >>> >>> On Wed, Nov 11, 2015 at 9:53 AM, yalin wang <yalin.wang2010@gmail.com> wrote: >>>> Use kmalloc instead of kzalloc, zero the memory is not needed. >>>> >>> why you want to do this? what problem you faces, and how this resolves the same? >> >> The patch fixes an inefficiency: explicitly zeroing memory that is then >> immediately overwritten 6 lines below is wasteful. > > It might fix previous kzalloc as well, though better not to do since > it's error prone. > yeah, i will send a new patch , >> >> Regards, >> Peter Hurley >> >>>> Signed-off-by: yalin wang <yalin.wang2010@gmail.com> >>>> --- >>>> drivers/mmc/card/block.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c >>>> index 23b6c8e..975cd3e 100644 >>>> --- a/drivers/mmc/card/block.c >>>> +++ b/drivers/mmc/card/block.c >>>> @@ -365,7 +365,7 @@ static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user( >>>> if (!idata->buf_bytes) >>>> return idata; >>>> >>>> - idata->buf = kzalloc(idata->buf_bytes, GFP_KERNEL); >>>> + idata->buf = kmalloc(idata->buf_bytes, GFP_KERNEL); >>>> if (!idata->buf) { >>>> err = -ENOMEM; >>>> goto idata_err; >>>> -- >>>> 1.9.1 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ > > > > -- > With Best Regards, > Andy Shevchenko -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 23b6c8e..975cd3e 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -365,7 +365,7 @@ static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user( if (!idata->buf_bytes) return idata; - idata->buf = kzalloc(idata->buf_bytes, GFP_KERNEL); + idata->buf = kmalloc(idata->buf_bytes, GFP_KERNEL); if (!idata->buf) { err = -ENOMEM; goto idata_err;
Use kmalloc instead of kzalloc, zero the memory is not needed. Signed-off-by: yalin wang <yalin.wang2010@gmail.com> --- drivers/mmc/card/block.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)