Hi Chao,
I have a question about the below flag for decompression.
STEP_DECOMPRESS_NOWQ, /* handle normal cluster data inplace */
According to the comment, you added this for using inplace
decompression but inplace decompression mode is not being activated
now, since we are setting STEP_DECOMPRESS right after bio_add_page().
if (bio_add_page(bio, page, blocksize, 0) < blocksize)
goto submit_and_realloc;
/* tag STEP_DECOMPRESS to handle IO in wq */
ctx = bio->bi_private;
if (!(ctx->enabled_steps & (1 << STEP_DECOMPRESS)))
ctx->enabled_steps |= 1 << STEP_DECOMPRESS;
Did you mean to deactivate inplace decompression mode on purpose,
since it had an issue? I am a little bit confused about this.
Hi Daeho,
On 2020/9/9 12:43, Daeho Jeong wrote:
> Hi Chao,
>
> I have a question about the below flag for decompression.
>
> STEP_DECOMPRESS_NOWQ, /* handle normal cluster data inplace */
>
> According to the comment, you added this for using inplace
I added this for the condition that: in compressed inode, partial clusters are
written as normal (non-compressed) one due to bad compress ratio, during reading
data in normal cluster, we don't need to queue them in workqueue, instead, we
can just handle them in IRQ context (end_io()).
That says, if all pages in bio are non-compressed, we tag step w/ STEP_DECOMPRESS_NOWQ,
once there is at least one page is compressed, we change step to
STEP_DECOMPRESS.
> decompression but inplace decompression mode is not being activated
'inplace decompression' means decompress in
a. reader thread or
b. IRQ context ?
Thanks
> now, since we are setting STEP_DECOMPRESS right after bio_add_page().
>
> if (bio_add_page(bio, page, blocksize, 0) < blocksize)
> goto submit_and_realloc;
>
> /* tag STEP_DECOMPRESS to handle IO in wq */
> ctx = bio->bi_private;
> if (!(ctx->enabled_steps & (1 << STEP_DECOMPRESS)))
> ctx->enabled_steps |= 1 << STEP_DECOMPRESS;
>
> Did you mean to deactivate inplace decompression mode on purpose,
> since it had an issue? I am a little bit confused about this.
>
>
> _______________________________________________
> Linux-f2fs-devel mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> .
>
Got it. I misunderstood that is some residue of trying to implement
softirq context decompression. :)
2020년 9월 9일 (수) 오후 4:15, Chao Yu <[email protected]>님이 작성:
>
> Hi Daeho,
>
> On 2020/9/9 12:43, Daeho Jeong wrote:
> > Hi Chao,
> >
> > I have a question about the below flag for decompression.
> >
> > STEP_DECOMPRESS_NOWQ, /* handle normal cluster data inplace */
> >
> > According to the comment, you added this for using inplace
>
> I added this for the condition that: in compressed inode, partial clusters are
> written as normal (non-compressed) one due to bad compress ratio, during reading
> data in normal cluster, we don't need to queue them in workqueue, instead, we
> can just handle them in IRQ context (end_io()).
>
> That says, if all pages in bio are non-compressed, we tag step w/ STEP_DECOMPRESS_NOWQ,
> once there is at least one page is compressed, we change step to
> STEP_DECOMPRESS.
>
> > decompression but inplace decompression mode is not being activated
>
> 'inplace decompression' means decompress in
> a. reader thread or
> b. IRQ context ?
>
> Thanks
>
> > now, since we are setting STEP_DECOMPRESS right after bio_add_page().
> >
> > if (bio_add_page(bio, page, blocksize, 0) < blocksize)
> > goto submit_and_realloc;
> >
> > /* tag STEP_DECOMPRESS to handle IO in wq */
> > ctx = bio->bi_private;
> > if (!(ctx->enabled_steps & (1 << STEP_DECOMPRESS)))
> > ctx->enabled_steps |= 1 << STEP_DECOMPRESS;
> >
> > Did you mean to deactivate inplace decompression mode on purpose,
> > since it had an issue? I am a little bit confused about this.
> >
> >
> > _______________________________________________
> > Linux-f2fs-devel mailing list
> > [email protected]
> > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> > .
> >